patch.diff: avoid calling workingctx().manifest()
Right now, to generate the manifest of the working dir, we have to
perform a full walk of the working dir, which will be very slow,
especially if we're interested in only a small part of it.
Since we use the manifest only to find out the mode of files for git
patches, manually build an execf function to do it.
This should fix
issue567.
syntax: glob
*.elc
*.orig
*.rej
*~
*.o
*.so
*.pyc
*.swp
*.prof
tests/.coverage*
tests/annotated
tests/*.err
build
contrib/hgsh/hgsh
dist
doc/*.[0-9]
doc/*.[0-9].gendoc.txt
doc/*.[0-9].{x,ht}ml
MANIFEST
patches
mercurial/__version__.py
.DS_Store
syntax: regexp
^\.pc/
Output/Mercurial-[0-9.]*.exe