gc: on osx fontforge-config.h *must* be included before ffglib.h.
    At any case, since calloc() is being tweaked then the fontforge-config.h
    doesn't help to be explicitly the first include file just to be sure.
Merge pull request #1317 from monkeyiq/2014apr/gcupdate1

gc: on osx fontforge-config.h *must* be included before ffglib.h.