Document FreeBSD quirk. Fix FreeBSD build.
Document FreeBSD quirk. Fix FreeBSD build.

tecnovert/particl-core,tecnovert/particl-core,particl/particl-core,particl/particl-core,particl/particl-core,particl/particl-core,tecnovert/particl-core,tecnovert/particl-core,particl/particl-core,particl/particl-core,tecnovert/particl-core,tecnovert/particl-core