Document release process

[pascalchevrel]

I think it would be good to start documenting a release process so as to not forget anything when the time comes and be able to release future versions with less work :)

Dumping here the things I can think of from the top of my head:

• create a branch for the new release
• update version number in VERSION in this branch (probably in a XX.XX.dev until it is released)
• ask a few existing moonmoon users to test the new version (I maintain the one at mozfr.org and I know the webdev that uses it for mozilla-hispano.org, that's a start for testing)
• extract l10n strings and ping localizers when we have some ;)
• update contributors list and any date related mentions
• potentially create a patch from the previous version for people that would want to patch their existing moonmoon setup?
• create release notes listing all the changes (major and minors) )since the previous version, that means looking at the git log
• promote some form of feedback channel to report bugs (I guess moonmoon twitter account would work for that)
• tweet/blog about it
• create a wiki page listing those requirements
• lots of things I am not thinking about :)

[pascalchevrel]

uncomment the return; line in extract_l10n.php or don't ship the l10n strings extraction tool with moonmoon