PLAY: remove unused dos.h.
PLAY: remove beep.
PLAY: comment out tokens after #endifs.
PLAY: rename select to prevent conflicts.
PLAY: fix implicit declarations.
PLAY: fix missing initialisers.
PLAY: fix multiple assignments.
PLAY: fix prototypes in prjctor.h.
PLAY: fix missing type in parameter.
Move 6x6 system font into a common directory.
PLAY: fix font header types.
Move raster font into a common directory.
PLAY: fix myInt union size.
PLAY: replace to_upper.

to_upper clobbers the source which could be constant.
Move jfile into a common directory.
PLAY: switch to standard file routines.
Refactor non-portable pointer manipulation routines.
Move DOS register types into a common directory.
PLAY: STATIC_ASSERT structure sizes.
PLAY: use WORD (2 bytes) and LONG (4 bytes) for portability.