Added preparation for GPU hardware accelerated solvers for BulletSoftBody (OpenCL and DirectCompute backends will follow)

Added assert to check for positive masses in btCompoundShape::calculatePrincipalAxisTransform, see Issue 399
Fixes for LLVM/GCC compilation issue in btSequentialImpulseConstraintSolver
(Untested) fix for Linux 64bit compilation Issue 409

CMakeLists.txt

@@ -7,6 +7,11 @@ SET(MSVC_INCREMENTAL_DEFAULT ON)
 PROJECT(BULLET_PHYSICS)
 SET(BULLET_VERSION 2.76)
 
+IF(COMMAND cmake_policy)
+   cmake_policy(SET CMP0003 NEW)
+ENDIF(COMMAND cmake_policy)
+
+
 IF (NOT CMAKE_BUILD_TYPE)
 # SET(CMAKE_BUILD_TYPE "Debug")
  SET(CMAKE_BUILD_TYPE "Release")
@@ -157,6 +162,8 @@ IF (USE_GLUT AND MSVC)
         remove_definitions(-D_WINDOWS )
 ENDIF()
 
+
+
 ELSE(WIN32)
 OPTION(USE_GLUT "Use Glut"	ON)
 ENDIF(WIN32)