[ftrfork] Fix the face order difference between POSIX and Carbon.

The fragmented resources in Suitcase and .dfont should be reordered
when post resource for Type1 is being restored, but reordering of
sfnt resources induces the different face order.  Now the ordering
is restricted to post resource only, to prevent the different order
issue  (e.g. the face index in the fontconfig cache generated with
Carbon framework is incompatible with that by FreeType2 without
Carbon framework.)  Found by Khaled Hosny and Hin-Tak Leung.

http://lists.gnu.org/archive/html/freetype-devel/2013-02/msg00035.html
http://lists.gnu.org/archive/html/freetype-devel/2013-12/msg00027.html

* src/base/ftrfork.c (FT_Raccess_Get_DataOffsets): Add a switch
`sort_by_res_id' to control the fragmented resource ordering.
* include/internal/ftrfork.h: Daclare new switch.
* src/base/ftobjs.c (IsMacResource): Enable the soring for post
resource, and disable the sorting for sfnt resource.