SWORD25: Fix regression in persistence code

The regression was introduced by commit e6ba26ff0d which wrote
coordinates of a rect as unsigned int when they were before written
as signed int. Since the load code was not modified it still expected
signed int. They are now again written as signed int. Any gamed saved
between commit e6ba26ff0d and this commit will therefore be corrupted.
SWORD25: Fix possible error in sound engine when loading a savegame

The error occurred when the save game was saved early in the game
before all the sound handles had been used. The unused handles only had
the handle type initialised (as kFreeHandle) so all the other fields had
random values. After loading the game the sound engine could erroneously
try to play one of these sound handle resulting in an error.
TSAGE: Renaming for R2R Landing Bay
TSAGE: Renaming for R2R Crane Controls
COMMON: Fix missing arjDecoder class variable init. CID 1002929

This fixes a couple of these variables by removing them as they
are unused or set-but-unused variables.
FULLPIPE: Implement MovGraphReact::pointInRegion()
FULLPIPE: Give more meaningful name to method parameter
NEVERHOOD: Split sprites from their scenes in modules 2100 and 2200

This also reduces inter-header dependencies
NEVERHOOD: Split sprites from their scenes in modules 1700 and 1800

This also reduces inter-header dependencies
NEVERHOOD: Split sprites from their scenes in module 1600
TSAGE: R2R bugfix for objects being removed and then readded incorrectly
TSAGE: Renaming for R2R Drive Room
TSAGE: Implemented semi-transparent door in R2R suit room
TSAGE: Renaming for R2R Lander Bay 2 Storage
TSAGE: Bugfix for rotating suits in R2R storage room
WINTERMUTE: Let pixel blending functions be inlined
NEVERHOOD: Split sprites from their scenes in modules 1300 and 1400
NEVERHOOD: Split sprites from their scenes in module 1200
FULLPIPE: Silence false positives about uninitialized variables in MSVC
NEVERHOOD: Split sprites from their scenes in modules 1000 and 1100