* Fixed OpenMP installation on MacOSX with gcc-6
- Modified makefile from gcc-5 to gcc-6
- Removed deprecated install instructions from doc (gcc-5 was automatically forced if available in makefile on OSX)
* Fixed OpenMP installation on MacOSX with gcc-6
- Modified makefile from gcc-5 to gcc-6
- Removed deprecated install instructions from doc (gcc-5 was automatically forced if available in makefile on OSX)