Merge pull request #50 from joakim-hove/Wells-GPR-WPR-IR

Wells gpr wpr ir
ADded #if BOOST_FILESYSTEM_VERSION == 2/3 to support both version 2 and version 3 of boost FS. IncludeTest will fail unconditionally on version 2
Added BOOST_FILESYSTEM_VERSION as cmake config option; default -> 3