convert: use git executable only, with subcommands

The latest GIT has some changes in the way it is installed. Only the 'git'
executable need to be in the path. All other commands are treated as sub
commands of 'git'.

hgext/convert/git.py

@@ -32,20 +32,20 b' class convert_git(converter_source):'
         if not os.path.exists(path + "/objects"):
             raise NoRepo("%s does not look like a Git repo" % path)
 
-        checktool('git-rev-parse', 'git')
+        checktool('git', 'git')
 
         self.path = path
 
     def getheads(self):
         if not self.rev:
-            return self.gitcmd('git-rev-parse --branches').read().splitlines()
+            return self.gitcmd('git rev-parse --branches').read().splitlines()
         else:
-            fh = self.gitcmd("git-rev-parse --verify %s" % self.rev)
+            fh = self.gitcmd("git rev-parse --verify %s" % self.rev)
             return [fh.read()[:-1]]
 
     def catfile(self, rev, type):
         if rev == "0" * 40: raise IOError()
-        fh = self.gitcmd("git-cat-file %s %s" % (type, rev))
+        fh = self.gitcmd("git cat-file %s %s" % (type, rev))
         return fh.read()
 
     def getfile(self, name, rev):
@@ -56,7 +56,7 b' class convert_git(converter_source):'
 
     def getchanges(self, version):
         self.modecache = {}
-        fh = self.gitcmd("git-diff-tree --root -m -r %s" % version)
+        fh = self.gitcmd("git diff-tree --root -m -r %s" % version)
         changes = []
         seen = {}
         for l in fh:
@@ -109,7 +109,7 b' class convert_git(converter_source):'
 
     def gettags(self):
         tags = {}
-        fh = self.gitcmd('git-ls-remote --tags "%s"' % self.path)
+        fh = self.gitcmd('git ls-remote --tags "%s"' % self.path)
         prefix = 'refs/tags/'
         for line in fh:
             line = line.strip()
@@ -126,7 +126,7 b' class convert_git(converter_source):'
     def getchangedfiles(self, version, i):
         changes = []
         if i is None:
-            fh = self.gitcmd("git-diff-tree --root -m -r %s" % version)
+            fh = self.gitcmd("git diff-tree --root -m -r %s" % version)
             for l in fh:
                 if "\t" not in l:
                     continue
@@ -134,7 +134,7 b' class convert_git(converter_source):'
                 changes.append(f)
             fh.close()
         else:
-            fh = self.gitcmd('git-diff-tree --name-only --root -r %s "%s^%s" --'
+            fh = self.gitcmd('git diff-tree --name-only --root -r %s "%s^%s" --'
                              % (version, version, i+1))
             changes = [f.rstrip('\n') for f in fh]
             fh.close()