web: include all files in the diffstat
The webutil.diffstat function now returns a diffstat template for each file
in the diff. It previously returned a template for each file returned by
ctx.files() which did not work well for merge changesets.
Minimal hgk check
$ echo "[extensions]" >> $HGRCPATH
$ echo "hgk=" >> $HGRCPATH
$ hg init repo
$ cd repo
$ echo a > a
$ hg ci -Am adda
adding a
$ hg debug-cat-file commit 0
tree a0c8bcbbb45c
parent 000000000000
author test 0 0
committer test 0 0
revision 0
branch default
adda