po/pot file attributes for textconf and diff (ie, make git diff on gettext files less useless)

.gitattributes

*.pot diff=msgcat
*.po diff=msgcat

gitconfig

# from http://stackoverflow.com/questions/2006351/gettext-po-files-under-version-control/11291001#11291001
# more verbose than my minimal version
[diff "msgcat"]
    textconv = msgcat --no-location --no-wrap --sort-output

# these diff defs use po_diff/pot_diff from https://github.com/alikins/gitconfig
# change the 'diff' in .gitattributes to diff=po or diff=pot to use

# convert po files to a less noisy
# # variant for display in git log -p etc
# # note that textconv does not affect
# # git-format-patch output
[diff "po"]
    textconv = po_diff
    cachetextconv = true

[diff "pot"]
    textconv = pot_diff
    # the line's it was picking for the "funcname"
    # context were kind of terrible for this case, so
    # just match a blank line so it's empty
    xfuncname = ^$
    cachetextconv = true