Cgal upgrade

[Vincent Habchi]

Folks,

I’m ready to upgrade the gis/cgal port to 4.1. This is the first version officially supporting Clang as a C/C++ compiler.

Unfortunately, while the libraries seem to compile all-right (but this is yet to be confirmed upstream), the demos fail to build because of bugs in Boost 1.51, that are going to be corrected in 1.52, which is not released yet.

Therefore: should I upgrade the Portfile and disable the demo variant, giving priority to Clang support, or wait until Boost 1.52 is out?

Thanks for any hint.

Cheers,
Vincent