tentative fix for the nasty lua crash

Lua is still disabled, I will reenabled it after I have some independant testing
[l10n] Swedish update: a few fuzzies and new strings
usermanual: first attempt of an index
brush masks: fix insertion of nodes
usermanual: index tweaking
usermanual: color balance
lua : minor cleanups
lua : remove systematic GC when ending execution of a script

gc will be decided by lua when needed

this is a leftover of the early design of the lua API and has no reason to be anymore
lua : clean stack properly

this could cause crash when calling lots of lua callbacks
(including importing large number of images)
Updated Danish translation in master
Fixed typo copie -> copy
changed credits
Merge pull request #292 from pryds/master

Updated Danish translation + fixed typo in control_jobs.c
lua : reenable lua. There are no more known lua bugs and we need general testing
Update French translation.
[l10n] Update German translation
rawspeed: import svn rev 570
(cherry picked from commit b4e252006dbda354a561a9371677b32772fc955b)
rawspeed: better diff on update
(cherry picked from commit de47a1e8cd7ae58d717d57b359b83339abbd376b)
lua: remove the lua lock, lua is always called with the gtk lock held
lua : optimisation, only call lua callbacks when a callback was registered