PJ: add header guards around includes.

Watcom is starting to run out of memory again.  This might help.
We'll also be cleaning up the header files over the next few commits
to reduce the number of files indirectly included.
PJ: remove some more traces of the hardware lock.

Previously jimk.h contained macros to substitute in widget code.
See commit 9cb785e5d1d7a08307a9a1b32eb0514cbe939d00.
PJ: clean up a3d.h.
PJ: clean up aaconfig.h.
PJ: clean up animinfo.h.
PJ: clean up argparse.h.
PJ: clean up auto.h.