Added warning flags for clang builds
Added warning flags for clang builds

offa/cpputest,basvodde/cpputest,basvodde/cpputest,basvodde/cpputest,cpputest/cpputest,cpputest/cpputest,offa/cpputest,basvodde/cpputest,offa/cpputest,cpputest/cpputest,offa/cpputest,cpputest/cpputest