1. Not MAKE_JOBS_SAFE.

2. Use MMFLAGS instead of MFLAGS as the compiler flags make variable.
The latter interacts somewhat poorly with make's own usage of the same
identifier. Do this by SUBST at post-extract time so nothing ever sees
the original form, and adjust patches to match.

Does not build (it cannot parse NetBSD's stdlib.h) but no longer
explodes randomly.

(dholland)