shiboken 1.2.1, fix build issue with Mavericks

Closes #23867.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
pyside 1.2.1 and pyside-tools 0.2.15
FFTW: Enable AVX support with clang compiler
added c++11 option to tbb, gmp, and libtiff
slightly loose superenv CXXFLAGS refurbishing to allow turning off
some warning-as-error's.