Add 0.9.15 zh_CN changes (sorry). Also clean up more of past mistake in lua (think I got 'em all now), and add a missing changelog entry.
1. Fix broken trainings/missions
2. Update translations (check fireforge for patches)
3. Check copyright headers
4. Changelog
5. Turn debug stuff off (frontend console output)
6. Update message in game server, update check for client version
7. Make a branch
8. Make packages
9. Test packages
10. Upload (hedgewars.org, fireforge.net, gna.org (rsync --delete -avr --rsh="ssh" . unc0rr@download.gna.org:/upload/hedgewars))
11. Post news (hedgewars.org, hedgewars forum, fireforge.net, gna.org, happypenguin, etc.)
12. Make tag (svn copy svn+ssh://unc0rr@svn.fireforge.net/svnroot/hedgewars/branches/0.9.7 svn+ssh://unc0rr@svn.fireforge.net/svnroot/hedgewars/tags/0.9.7 -m "Tag for 0.9.7 release")