qt4: Was using PATCH_EXE defined in PatchSupport, but had the include of  PatchSupport commented. This line has been uncommented and a comment to this effect was left.
nose: The URL for external_source contained the file to download, which it shouldn't. This caused build errors.
qimage2ndarray: Removed PatchSupport comment as no patching is happening here. Also, added SHA1 commented for the release in question.
gmp: Added more detail to comment at top about the cmake file. Removed extra quote in CONFIGURE_COMMAND that was causing build errors.
mpfr: Added more detailed introductor comment. Added an additional flag to the configure comment to help specify where gmp is just for clarity.
python: Added a patch to stop the buildem Python from including the system Python packages in sys.path for Mac. Without this patch, buildem Python may fail to install packages and use system versions instead of buildem versions or in the worse case link against system Python libraries/packages instead of buildem version.