bundle2: move bundle2 config option to section "experimental"

We highlight the fact that this is experimental by moving it to an "experimental"
section, and we match the config name with the server capability name
`bundle2-exp`.

mercurial/localrepo.py

@@ -305,7 +305,7 b' class localrepository(object):'
     def _restrictcapabilities(self, caps):
         # bundle2 is not ready for prime time, drop it unless explicitly
         # required by the tests (or some brave tester)
-        if self.ui.configbool('server', 'bundle2', False):
+        if self.ui.configbool('experimental', 'bundle2-exp', False):
             caps = set(caps)
             capsblob = bundle2.encodecaps(self.bundle2caps)
             caps.add('bundle2-exp=' + urllib.quote(capsblob))

mercurial/wireproto.py

@@ -585,7 +585,7 b' def _capabilities(repo, proto):'
         # otherwise, add 'streamreqs' detailing our local revlog format
         else:
             caps.append('streamreqs=%s' % ','.join(requiredformats))
-    if repo.ui.configbool('server', 'bundle2', False):
+    if self.ui.configbool('experimental', 'bundle2-exp', False):
         capsblob = bundle2.encodecaps(repo.bundle2caps)
         caps.append('bundle2-exp=' + urllib.quote(capsblob))
     caps.append('unbundle=%s' % ','.join(changegroupmod.bundlepriority))

tests/test-bundle2.t

@@ -174,8 +174,8 b' Create an extension to test bundle2 API'
   $ cat >> $HGRCPATH << EOF
   > [extensions]
   > bundle2=$TESTTMP/bundle2.py
-  > [server]
-  > bundle2=True
+  > [experimental]
+  > bundle2-exp=True
   > [ui]
   > ssh=python "$TESTDIR/dummyssh"
   > [web]