Fix C++ compiler errors in readdib.c.

Add required casts.
Cleanup monster2.c part 1.

Lines 1 to 1000.
Cleanup monster2.c part 2.

Lines 1001 to 2000.
Cleanup monster2.c part 3.

Lines 2001-3000.
Cleanup monster2.c part 4.

Lines 3001-4000.
Cleanup monster2.c part 5.

Lines 4001 to end.