* Newer versions of GCC (e.g., 4.7.3) support plugins on OS X out of the
  box, so no patch is necessary.

* Have to use previous GCC build (4.5.1) for libcutl/ODB compilation because
  of some problems 4.7.3 has with older as. See build-dist PATH settings.

  Because of that, we have to manually add 4.7.3 plugin headers to CPPFLAGS
  (see odb-configure).