keyword: obtain kwtemplater instance via repository at runtime

Wrapper functions of keyword extension are defined in reposetup(),
because they refer to kwtemplater instantiated in reposetup().

This patch makes them obtain kwtemplater instance via repository at
runtime.

This is a part of preparations for defining them statically.

hgext/keyword.py

@@ -671,6 +671,8 b' def reposetup(ui, repo):'
         '''Monkeypatch/wrap patch.patchfile.__init__ to avoid
         rejects or conflicts due to expanded keywords in working dir.'''
         orig(self, ui, gp, backend, store, eolmode)
+        kwt = getattr(getattr(backend, 'repo', None), '_keywordkwt', None)
+        if kwt:
         # shrink keywords read from working dir
         self.lines = kwt.shrinklines(self.fname, self.lines)
 
@@ -696,6 +698,9 b' def reposetup(ui, repo):'
 
     def kw_amend(orig, ui, repo, commitfunc, old, extra, pats, opts):
         '''Wraps cmdutil.amend expanding keywords after amend.'''
+        kwt = getattr(repo, '_keywordkwt', None)
+        if kwt is None:
+            return orig(ui, repo, commitfunc, old, extra, pats, opts)
         with repo.wlock():
             kwt.postcommit = True
             newid = orig(ui, repo, commitfunc, old, extra, pats, opts)
@@ -716,6 +721,9 b' def reposetup(ui, repo):'
         For the latter we have to follow the symlink to find out whether its
         target is configured for expansion and we therefore must unexpand the
         keywords in the destination.'''
+        kwt = getattr(repo, '_keywordkwt', None)
+        if kwt is None:
+            return orig(ui, repo, pats, opts, rename)
         with repo.wlock():
             orig(ui, repo, pats, opts, rename)
             if opts.get('dry_run'):
@@ -739,6 +747,9 b' def reposetup(ui, repo):'
 
     def kw_dorecord(orig, ui, repo, commitfunc, *pats, **opts):
         '''Wraps record.dorecord expanding keywords after recording.'''
+        kwt = getattr(repo, '_keywordkwt', None)
+        if kwt is None:
+            return orig(ui, repo, commitfunc, *pats, **opts)
         with repo.wlock():
             # record returns 0 even when nothing has changed
             # therefore compare nodes before and after
@@ -758,6 +769,9 b' def reposetup(ui, repo):'
     def kwfilectx_cmp(orig, self, fctx):
         if fctx._customcmp:
             return fctx.cmp(self)
+        kwt = getattr(self._repo, '_keywordkwt', None)
+        if kwt is None:
+            return orig(self, fctx)
         # keyword affects data size, comparing wdir and filelog size does
         # not make sense
         if (fctx._filenode is None and