Building clang/cling 3.5 for ROOT on Lion

[Chris Jones]

> I'll see if I can manage to build the whole ROOT 6 with -stdlib=libc++
> (without referencing any other piece from MacPorts). But that probably
> means that I shouldn't use OpenGL from the system, right?

Don't forget, you will also need to rebuild each and every port that 
root uses, that uses a c++ runtime against libc++ as well...

Chris