Wristwatch now partially functional.

id_us_2.c: Games can now be started from the wristwatch
ck_inter.c: (New file). Made a skeleton ck_inter.c so that the intermission routines can be placed here later on.
id_vh.c: Added in primitive graphic drawing routines.
ck_main.c, ck_play.c, ck_game.c: shuffled some things around, added some more bits and pieces.  There are a lot of global variables and extern declarations everywhere now.
Merge branch 'lemm_initial_wristwatch_support' into merge-test
We need to have NULL defined for id_us_2.c to compile