Sconstruct modified so that Blender build on 10.3 without any additionnal
download than source + darwin libs.
defaults settings correct for 10.3.
fixed bug # 1260 : added MT_NDEBUG flag at top-level.
[SCons] Build with Solid as default when enabling the gameengine in the build process
[SCons] Build solid and qhull from the extern directory and link statically against them
That was about it.
There are a few things that needs double checking:
* Makefiles
* Projectfiles
* All the other systems than Linux and Windows on which the build (with scons) has been successfully tested.