FindBoost: Add support for -clangNN variant names
This issue was created automatically from an original Mantis Issue. Further discussion may take place here.
If boost libraries are built with clang, their compiler name ends up being clang-darwin instead of xgcc. Because of this, the script fails to locate them.
Same problem with a selfcompiled clang 3.3 on windows. The boost library files are named
works around the problem.