i18n: sort by file when generating hg.pot
This will make the order more stable and give smaller patches when
translations merge in new and deleted strings from the hg.pot file.
Basic install:
$ make # see install targets
$ make install # do a system-wide install
$ hg debuginstall # sanity-check setup
$ hg # see help
See http://www.selenic.com/mercurial/ for detailed installation
instructions, platform-specific notes, and Mercurial user information.