Log Message:
Remove NOT_FOR_PLATFORM for Interix; that should be for technical
issues only, not licensing.

Add LICENSE=openmotif-license because this software is non-Free.

Set RESTRICTED, and NO_*_ON_CDROM because the license has complex
terms for "commercial product offering".

If $(OPSYS) is not in
  DragonFly FreeBSD Linux NetBSD OpenBSD
set NO_*_ON_FTP, because the license only grants distribution rights
for open source operating systems.

I believe this commit will still prevent openmotif from building on
Interix without setting ACCEPTABLE_LICENSES, and should also result in
all 4 of NO_*_ON_* being set on Interix.

There's too much make code to implement NO_*_ON_FTP-on-other-than-list
(munged from bsd.pkg.mk), but I didn't see a way to make
ONLY_FOR_PLATFORM run a makefile fragment on other platforms.