Allow vgtBigExplosion in low quality mode
Rationale: We already allow vgtExplosion, which is a smaller version. Without vgtBigExplosion, there is not *any* explosion effect.
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")