- introduce a FOAM_LD_LIBRARY_PATH variable to shadow
  DYLD_LIBRARY_PATH on MacOS.

  The DYLD_LIBRARY_PATH and LD_LIBRARY_PATH cannot be modified via sub
  shells etc when SIP is active. This helps circumvent these
  restrictions, which is obviously a hack, but seems to be required.

COMP: disable -ftrapping-math in geompack for MacOS