addr and taddr don't have to be defined any more, so that <sys/mman.h>
can be included for proper prototypes of munmap() and friends.
- rename our GETPID to MINIX_GETPID to avoid a name conflict with
other sources
- PM needs its own munmap() and munmap_text() to avoid sending messages
to VM at the startup phase. It *does* want to do that, but only
after initialising. So they're called again with unmap_ok set to 1
later.
- getnuid(), getngid() implementation