tests: fix up some import statements caught by Python 3

I'm curious how the import checker manages to be so much more
pedantic in Python 3, but not enough to bother exploring.

Differential Revision: https://phab.mercurial-scm.org/D5240

tests/test-remotefilelog-bundle2-legacy.t

@@ -1,93 +1,93 b''
   $ PYTHONPATH=$TESTDIR/..:$PYTHONPATH
   $ export PYTHONPATH
 
   $ . "$TESTDIR/remotefilelog-library.sh"
 
 generaldelta to generaldelta interactions with bundle2 but legacy clients
 without changegroup2 support
   $ cat > testcg2.py << EOF
+  > import sys
   > from mercurial import changegroup, registrar, util
-  > import sys
   > cmdtable = {}
   > command = registrar.command(cmdtable)
   > @command('testcg2', norepo=True)
   > def testcg2(ui):
   >     if not util.safehasattr(changegroup, 'cg2packer'):
   >         sys.exit(80)
   > EOF
   $ cat >> $HGRCPATH << EOF
   > [extensions]
   > testcg2 = $TESTTMP/testcg2.py
   > EOF
   $ hg testcg2 || exit 80
 
   $ cat > disablecg2.py << EOF
-  > from mercurial import changegroup, util, error
+  > from mercurial import changegroup, error, util
   > deleted = False
   > def reposetup(ui, repo):
   >     global deleted
   >     if deleted:
   >         return
   >     packermap = changegroup._packermap
   >     # protect against future changes
   >     if len(packermap) != 3:
   >         raise error.Abort('packermap has %d versions, expected 3!' % len(packermap))
   >     for k in ['01', '02', '03']:
   >         if not packermap.get(k):
   >             raise error.Abort("packermap doesn't have key '%s'!" % k)
   > 
   >     del packermap['02']
   >     deleted = True
   > EOF
 
   $ hginit master
   $ grep generaldelta master/.hg/requires
   generaldelta
   $ cd master
 preferuncompressed = False so that we can make both generaldelta and non-generaldelta clones
   $ cat >> .hg/hgrc <<EOF
   > [remotefilelog]
   > server=True
   > [experimental]
   > bundle2-exp = True
   > [server]
   > preferuncompressed = False
   > EOF
   $ echo x > x
   $ hg commit -qAm x
 
   $ cd ..
 
   $ hgcloneshallow ssh://user@dummy/master shallow -q --pull --config experimental.bundle2-exp=True
   1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
   $ cd shallow
   $ cat >> .hg/hgrc << EOF
   > [extensions]
   > disablecg2 = $TESTTMP/disablecg2.py
   > EOF
 
   $ cd ../master
   $ echo y > y
   $ hg commit -qAm y
 
   $ cd ../shallow
   $ hg pull -u
   pulling from ssh://user@dummy/master
   searching for changes
   adding changesets
   adding manifests
   adding file changes
   added 1 changesets with 0 changes to 0 files
   new changesets d34c38483be9
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
 
   $ echo a > a
   $ hg commit -qAm a
   $ hg push
   pushing to ssh://user@dummy/master
   searching for changes
   remote: adding changesets
   remote: adding manifests
   remote: adding file changes
   remote: added 1 changesets with 1 changes to 1 files

tests/test-remotefilelog-cacheprocess.t

@@ -1,122 +1,124 b''
   $ PYTHONPATH=$TESTDIR/..:$PYTHONPATH
   $ export PYTHONPATH
 
   $ . "$TESTDIR/remotefilelog-library.sh"
 
   $ hg init repo
   $ cd repo
   $ cat >> .hg/hgrc <<EOF
   > [remotefilelog]
   > server=True
   > EOF
   $ echo x > x
   $ echo y > y
   $ echo z > z
   $ hg commit -qAm xy
   $ cd ..
 
   $ cat > cacheprocess-logger.py <<EOF
-  > import sys, os, shutil
+  > import os
+  > import shutil
+  > import sys
   > f = open('$TESTTMP/cachelog.log', 'w')
   > srccache = os.path.join('$TESTTMP', 'oldhgcache')
   > def log(message):
   >     f.write(message)
   >     f.flush()
   > destcache = sys.argv[-1]
   > try:
   >     while True:
   >         cmd = sys.stdin.readline().strip()
   >         log('got command %r\n' % cmd)
   >         if cmd == 'exit':
   >             sys.exit(0)
   >         elif cmd == 'get':
   >             count = int(sys.stdin.readline())
   >             log('client wants %r blobs\n' % count)
   >             wants = []
   >             for _ in xrange(count):
   >                 key = sys.stdin.readline()[:-1]
   >                 wants.append(key)
   >                 if '\0' in key:
   >                     _, key = key.split('\0')
   >                 srcpath = os.path.join(srccache, key)
   >                 if os.path.exists(srcpath):
   >                     dest = os.path.join(destcache, key)
   >                     destdir = os.path.dirname(dest)
   >                     if not os.path.exists(destdir):
   >                         os.makedirs(destdir)
   >                     shutil.copyfile(srcpath, dest)
   >                 else:
   >                     # report a cache miss
   >                     sys.stdout.write(key + '\n')
   >             sys.stdout.write('0\n')
   >             for key in sorted(wants):
   >                 log('requested %r\n' % key)
   >             sys.stdout.flush()
   >         elif cmd == 'set':
   >             assert False, 'todo writing'
   >         else:
   >             assert False, 'unknown command! %r' % cmd
   > except Exception as e:
   >     log('Exception! %r\n' % e)
   >     raise
   > EOF
 
   $ cat >> $HGRCPATH <<EOF
   > [remotefilelog]
   > cacheprocess = python $TESTTMP/cacheprocess-logger.py
   > EOF
 
 Test cache keys and cache misses.
   $ hgcloneshallow ssh://user@dummy/repo clone -q
   3 files fetched over 1 fetches - (3 misses, 0.00% hit ratio) over *s (glob)
   $ cat cachelog.log
   got command 'get'
   client wants 3 blobs
   requested 'master/11/f6ad8ec52a2984abaafd7c3b516503785c2072/1406e74118627694268417491f018a4a883152f0'
   requested 'master/39/5df8f7c51f007019cb30201c49e884b46b92fa/69a1b67522704ec122181c0890bd16e9d3e7516a'
   requested 'master/95/cb0bfd2977c761298d9624e4b4d4c72a39974a/076f5e2225b3ff0400b98c92aa6cdf403ee24cca'
   got command 'set'
   Exception! AssertionError('todo writing',)
 
 Test cache hits.
   $ mv hgcache oldhgcache
   $ rm cachelog.log
   $ hgcloneshallow ssh://user@dummy/repo clone-cachehit -q
   3 files fetched over 1 fetches - (0 misses, 100.00% hit ratio) over *s (glob)
   $ cat cachelog.log | grep -v exit
   got command 'get'
   client wants 3 blobs
   requested 'master/11/f6ad8ec52a2984abaafd7c3b516503785c2072/1406e74118627694268417491f018a4a883152f0'
   requested 'master/39/5df8f7c51f007019cb30201c49e884b46b92fa/69a1b67522704ec122181c0890bd16e9d3e7516a'
   requested 'master/95/cb0bfd2977c761298d9624e4b4d4c72a39974a/076f5e2225b3ff0400b98c92aa6cdf403ee24cca'
 
   $ cat >> $HGRCPATH <<EOF
   > [remotefilelog]
   > cacheprocess.includepath = yes
   > EOF
 
 Test cache keys and cache misses with includepath.
   $ rm -r hgcache oldhgcache
   $ rm cachelog.log
   $ hgcloneshallow ssh://user@dummy/repo clone-withpath -q
   3 files fetched over 1 fetches - (3 misses, 0.00% hit ratio) over *s (glob)
   $ cat cachelog.log
   got command 'get'
   client wants 3 blobs
   requested 'x\x00master/11/f6ad8ec52a2984abaafd7c3b516503785c2072/1406e74118627694268417491f018a4a883152f0'
   requested 'y\x00master/95/cb0bfd2977c761298d9624e4b4d4c72a39974a/076f5e2225b3ff0400b98c92aa6cdf403ee24cca'
   requested 'z\x00master/39/5df8f7c51f007019cb30201c49e884b46b92fa/69a1b67522704ec122181c0890bd16e9d3e7516a'
   got command 'set'
   Exception! AssertionError('todo writing',)
 
 Test cache hits with includepath.
   $ mv hgcache oldhgcache
   $ rm cachelog.log
   $ hgcloneshallow ssh://user@dummy/repo clone-withpath-cachehit -q
   3 files fetched over 1 fetches - (0 misses, 100.00% hit ratio) over *s (glob)
   $ cat cachelog.log | grep -v exit
   got command 'get'
   client wants 3 blobs
   requested 'x\x00master/11/f6ad8ec52a2984abaafd7c3b516503785c2072/1406e74118627694268417491f018a4a883152f0'
   requested 'y\x00master/95/cb0bfd2977c761298d9624e4b4d4c72a39974a/076f5e2225b3ff0400b98c92aa6cdf403ee24cca'
   requested 'z\x00master/39/5df8f7c51f007019cb30201c49e884b46b92fa/69a1b67522704ec122181c0890bd16e9d3e7516a'