SCI/TODO

• check for places that use char or unsigned char for boolean values, and change those to bool. Even nicer would be to change it to use enum types whose value names express the intention (SearchOptions.RECURSIVE, GraphicsScaleOptions.2X, etc), but just going for bool will already be a big improvement.
• Change #define lists into enums
• Rearrange the files under engines/sci. Some source files should also be renamed for clarity.
• Convert stuff from "C pseudo classes" to real classes.
• Replace various generic FreeSCI code by their ScummVM counterparts, where it make sense.
• Not specific to SCI, but: Replace "struct tm" in common/system.h (and places that implement/use it) by a custom struct, which would be a (partial) clone of struct tm, something like Common::OSystem::Time. That way, we wouldn't have to use <time.h> anymore anywhere.
• change the many nice existing function documentation comments to use doxygen syntax
• Turn code into templates in following files (now they generate code via #defines):
  • gfx/gfx_pixmap_scale.cpp
  • gfx/picfill.cpp
• Check old FreeSCI-scummvm branch / repos by Jordi for change that could be salvaged, e.g. the files sfx/device/scumm-midi.cpp and sfx/softseq/scumm-adlib.cpp, or the modifications to the SCI debugger to use the ScummVM console, and stuff.
• make the SCI tools compilable (to avoid bitrot, while we change code that they depend on), and finally usable again.
• rename the sfx/ dir to sound/ or audio/ (it doesn't just deal with "sound effects).