buildenv/1.2.x/osx: set -jX in MAKEFLAGS to value of 'hw.ncpu' sysctl.
buildenv/1.2.x/osx: set -jX in MAKEFLAGS to value of 'hw.ncpu' sysctl.

Could use 'hw.physicalcpu' to limit the level of parallelism to
the number of physical cores, but let us try this first.

ccpgames/mumble-releng,ccpgames/mumble-releng