[Libreoffice] --with-num-cpus/--with-max-jobs and gbuild

So, the gbuild stuff uses -j$(MAXPROCESS) and we have configure options
tuned for build/dmake where
--with-num-cpus is the number of -PX given to "build" and sets
BUILD_NCPUS
--with-max-jobs is the number of -PX given to "dmake" and sets
BUILD_MAX_JOBS
nothing sets MAXPROCESS

so, we could e.g. change MAXPROCESS to be BUILD_MAX_JOBS and -jX to the
same X as dmake -X was. Or we could invert our current allocation of
cpus and set the ncpus as the value for dmake && gmake, which is sort of
the standard practice, i.e. make --with-num-cpus control dmake/gmake and
set max-jobs as the no of parallel builds.

Thoughts ?

C.