1) (win32window) don't convert char to wide, use char direct to window.
2) (CMakeLists) Don't link one library as static CPPLIB and no others (mismatched allocations)
3) (macros) Fix Gwen macros for mingw64 on windows build. (changes are by compiler(msc_ver) not platform)
4) (FileUtils) sprintf_s reference by platform, not compiler (mingw64 support)
5) (b3OpenCLUtils) fix bad define name _MSVC_VER->_MSC_VER
6) (compoundCollision) remove unused variables, simplify operation.
7) (impulseconstraint) remove duplicated code block
URDF import demo: add COLLADA .dae file support
add FiniteElementMethod demo, extracted from the OpenTissue library (under the zlib license)
don't crash if loading an invalid STL file
add comparison with Assimp for COLLADA file loading (disabled by default, to avoid library dependency)
Gwen: disable some flags that make the build incompatible
improve btMultiBody version of URDF reader (still work-in-progress)
enabled planar joint for btMultiBody (untested)
enable loading from relative path for .stl meshes
