url: add trailing slashes to URLs with hostnames that don't have one

This works around a potential issue in Python 2.4 where cloning a repo
with a URL like http://foo:8080 would cause urllib2 to query on
http://foo:8080?cmd=capabilities instead of
http://foo:8080/?cmd=capabilities.

In the past, this issue has been masked by the fact that
url.getauthinfo() added a trailing slash when it was missing.

mercurial/url.py

@@ -156,7 +156,7 b' class url(object):'
         >>> str(url('http://localhost:80/'))
         'http://localhost:80/'
         >>> str(url('http://localhost:80'))
-        'http://localhost:80'
+        'http://localhost:80/'
         >>> str(url('bundle:foo'))
         'bundle:foo'
         >>> str(url('path'))
@@ -185,8 +185,7 b' class url(object):'
                 s += self.host
         if self.port:
             s += ':' + urllib.quote(self.port)
-        if ((self.host and self.path is not None) or
-            (self.host and self.query or self.fragment)):
+        if self.host:
             s += '/'
         if self.path:
             s += urllib.quote(self.path, safe=self._safepchars)

tests/test-http-branchmap.t

@@ -30,7 +30,7 b''
   $ echo bar >> b/foo
   $ hg -R b ci -m bar
   $ hg --encoding utf-8 -R b push
-  pushing to http://localhost:$HGPORT1
+  pushing to http://localhost:$HGPORT1/
   searching for changes
   remote: adding changesets
   remote: adding manifests

tests/test-schemes.t

@@ -26,7 +26,7 b' check that {1} syntax works'
   $ hg incoming --debug parts://localhost
   using http://localhost:$HGPORT/
   sending capabilities command
-  comparing with parts://localhost
+  comparing with parts://localhost/
   sending heads command
   searching for changes
   sending known command