improve some comments and docstrings, fixing issues found when spell checking

mercurial/context.py

@@ -237,8 +237,8 b' class changectx(object):'
 
     def extinct(self):
         """True if the changeset is extinct"""
-        # We should just compute a cache a check against it.
-        # see revset implementation for details
+        # We should just compute a cache and check against it.
+        # See revset implementation for details.
         #
         # But this naive implementation does not require cache
         if self.phase() <= phases.public:

mercurial/hgweb/server.py

@@ -12,7 +12,7 b' from mercurial.hgweb import common'
 from mercurial.i18n import _
 
 def _splitURI(uri):
-    """ Return path and query split from uri
+    """Return path and query that has been split from uri
 
     Just like CGI environment, the path is unquoted, the query is
     not.

mercurial/localrepo.py

@@ -300,7 +300,7 b' class localrepository(object):'
         """hiddenrevs: revs that should be hidden by command and tools
 
         This set is carried on the repo to ease initialisation and lazy
-        loading it'll probably move back to changelog for efficiency and
+        loading; it'll probably move back to changelog for efficiency and
         consistency reason
 
         Note that the hiddenrevs will needs invalidations when
@@ -2539,7 +2539,7 b' class localrepository(object):'
         # uncompressed only if compatible.
 
         if not stream:
-            # if the server explicitly prefer to stream (for fast LANs)
+            # if the server explicitly prefers to stream (for fast LANs)
             stream = remote.capable('stream-preferred')
 
         if stream and not heads:

mercurial/lock.py

@@ -122,7 +122,7 b' class lock(object):'
     def release(self):
         """release the lock and execute callback function if any
 
-        If the lock have been acquired multiple time, the actual release is
+        If the lock has been acquired multiple time, the actual release is
         delayed to the last release call."""
         if self.held > 1:
             self.held -= 1