Handle compiler settings for WIN32/*nix.
Handle compiler settings for WIN32/*nix.

Use CMAKE_POSITION_INDEPENDENT_CODE rather than setting -fPIC ourselves.
Presumably this won't set -fPIC when it isn't needed (i.e. windows).

Use -std=c++11 for our C++ code, except under WIN32, in which case use
-std=gnu++11 (currently needed for mingw-w64 under msys2).

seec-team/seec,mheinsen/seec,mheinsen/seec,mheinsen/seec,seec-team/seec,mheinsen/seec,mheinsen/seec,seec-team/seec,seec-team/seec,seec-team/seec