CGE2: Fully implement the save/load system.

Now the toolbar is working too after loading.
CGE2: Remove unnecessary warning and debug info from showTitle().
CGE2: Implement loading from the Launcher.
PRINCE: Background animations update. O_PUTBACKANIM(), O_REMBACKANIM(), O_ANIMUPDATEON(), O_ANIMUPDATEOFF()
PRINCE: O_GETOBJDATA(), O_SETOBJDATA()
SCUMM: Add support for CD audio tracks in the Steam versions of Loom

Many Thanks to Ben Castricum for the original patch
OPENGLSDL: Don't ignore events after user-initiated resizes.
CGE2: Add extra clipping to Bitmap::hide
Merge pull request #470 from bluegr/Lucasarts_Steam

SCUMM: Add support for Steam versions of Indy 3, Indy 4, Loom and Dig
SCUMM: Remove empty line before license header.
SCUMM: Use spaces instead of tabs in comments.
SCUMM: Remove unused variable.
SCUMM: Slight formatting fixes.
SCUMM: Fix a subtle bug in Sound::getCDStatus() for Loom Steam
SCUMM: Simplify index file handling for Steam versions.

This also makes sure that all extra needed detection data for the Steam
releases is located inside detection.cpp.
SCUMM: Cleanup.
I18N: Update French translation
SWORD1: Tweak MPEG-2 cutscenes error message

Beside making the message slightly better imho, it is also now
identical to the same message in BS2 and also more coherent with
the DXA message.
PRINCE: checkSeq() update
PRINCE: installObjects(), setObjId(), O_PUTOBJECT(), O_REMOBJECT(). checkMob(), showObjects(), O_GETRND() update