compile in mac

Hi,
It was not compiling on mac for two reasons:
1. clang is veary peacky, it wont allow you to pass c++ options (-std=c++11) to c code (sdl2)
2. biicode implicit rules for linking with GLU are wrong (already fixed in development branch) so you need to disable them and explicitly link with GLU

Now it compiles, tests pass but all shapes are spheres :disappointed: :
![noshapes](https://cloud.githubusercontent.com/assets/611228/4767152/c49d4274-5b5a-11e4-92cb-6e16c7b514e9.png)