Bug 939622 - Remove LIBXUL_LIBRARY for intermediate libs that end up in gkmedias. r=gps

What LIBXUL_LIBRARY does is:
  - Imply FORCE_STATIC_LIB
  - Build with -DIMPL_LIBXUL
  - Build with -DMOZILLA_INTERNAL_API

Those intermediate libs that end up in gkmedias and have LIBXUL_LIBRARY defined
in their moz.build are all third party code (or handled like third party code).
Besides FORCE_STATIC_LIB, none of the side effects of LIBXUL_LIBRARY should be
needed.
Bug 939074 - Infer LIBXUL_LIBRARY from FINAL_LIBRARY. r=gps
Bug 939074 - Remove most LIBXUL_LIBRARY. rs=gps
Bug 939632 - Allow LIBRARY_NAME to be omitted when FINAL_LIBRARY is defined. r=gps
Bug 939632 - Remove LIBRARY_NAME for leaf libraries. r=gps
Bug 938437 - Replace nsStaticXULComponents.cpp with smart use of sections. r=bsmedberg
Bug 938526 - Ignore import libraries when dealing with --extract in expandlibs_exec.py. r=khuey
Resync with patch queue