Makefile: macos fix for nb proc detection
cmake: macos fix, "sam" needs CoreFoundation framework
cmake: ilmbase, add include subdir
cmake: OpenJpeg, add include subdir

I find no solution to dynamically search for the name of the
subdirectory.
cmake: IlmBase, add missing dependency
travis: cmake now search in all homebrew packages
cmake: don't modify default boost_use_multithread option