Fix 'unused variable' warnings

[fingolfin]

This fixes a bunch of warnings about unused variables I receive when compiling ScummVM on Mac OS X 10.8

[digitall]

@fingolfin : Thanks for the fixes or at least for flagging up these issues. I don't think merging this as-is is OK as it resulting in a load of commented out code...

[digitall]

However, the engine authors for AGI ( @sev- ), MADS ( @bluegr ), MOHAWK Riven ( @clone2727 ), NEVERHOOD, SWORD25 and core team for common/unzip.cpp, image/codecs/mjpeg.cpp and gui/EventRecorder.cpp should deal with closing the issues either by fixing the errorneously unused code or by deleting...

[bluegr]

Thanks for your work! This looks good to be merged. All of the code commented out is unused.

I'll try and split this into separate commits, as this can't be committed as one...

Regarding AGI: I'll set it to use some of the unused code in a subsequent commit.

[bluegr]

All of this has been pushed to master as several different commits. I've added the Amiga palettes to AGI too.

Closing