Small fixes here and there.
Removed support for D9DX completely.
Big edit to make all code use the new tmrval_t type for timers instead of int64_t, and (because of that) added timer.h to many files.
Updated to make 'port92' (from mem.ch) a device in devices/system/port92.c
Several small changes and cleanups.
Big edit to replace the 'void *' arguments with a new priv_t typedef to allow better enforcing of types in future cleanup rounds.
