scmutil: introduce filecache
The idea is being able to associate a file with a property, and watch
that file stat info for modifications when we decide it's important for it to
be up-to-date. Once it changes, we recreate the object.
On filesystems that can't uniquely identify a file, we always recreate.
As a consequence, localrepo.invalidate() will become much less expensive in the
case where nothing changed on-disk.
syntax: glob
*.elc
*.orig
*.rej
*~
*.mergebackup
*.o
*.so
*.dll
*.pyd
*.pyc
*.pyo
*$py.class
*.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
MANIFEST.in
patches
mercurial/__version__.py
mercurial.egg-info
Output/Mercurial-*.exe
.DS_Store
tags
cscope.*
i18n/hg.pot
locale/*/LC_MESSAGES/hg.mo
hgext/__index__.py
# files installed with a local --pure build
mercurial/base85.py
mercurial/bdiff.py
mercurial/diffhelpers.py
mercurial/mpatch.py
mercurial/osutil.py
mercurial/parsers.py
syntax: regexp
^\.pc/
^\.(pydev)?project