lfs: add the '{lfsattrs}' template keyword to '{lfs_files}'
This provides access to the metadata dictionary contained within the tracked
pointer file. The OID is probably the most important attribute, and has its own
keyword. But we might as well have this for completeness.
I liked {pointer} better, but couldn't make it work with the singular/plural
forms.
#require execbit
$ hg init repo
$ cd repo
$ echo foo > foo
$ chmod 644 foo
$ hg ci -qAm '644'
$ chmod 755 foo
$ hg ci -qAm '755'
reverting to rev 0
$ hg revert -a -r 0
reverting foo
$ hg st
M foo
$ hg diff --git
diff --git a/foo b/foo
old mode 100755
new mode 100644
$ cd ..