added existing demos to CMake build system

thanks to http://code.google.com/p/bullet/issues/detail?id=209
Added helper method 'getAxis' to btQuaternion,
thanks to Tully.Foote, http://code.google.com/p/bullet/issues/detail?id=205

Demos/Raytracer/CMakeLists.txt

@@ -0,0 +1,25 @@
+# This is basically the overall name of the project in Visual Studio this is the name of the Solution File
+
+
+# For every executable you have with a main method you should have an add_executable line below.
+# For every add executable line you should list every .cpp and .h file you have associated with that executable.  
+
+
+
+# You shouldn't have to modify anything below this line 
+########################################################
+
+
+INCLUDE_DIRECTORIES(
+${BULLET_PHYSICS_SOURCE_DIR}/src ${BULLET_PHYSICS_SOURCE_DIR}/Demos/OpenGL }
+)
+
+LINK_LIBRARIES(
+OpenGLSupport BulletDynamics  BulletCollision LinearMath    ${GLUT_glut_LIBRARY} ${OPENGL_gl_LIBRARY} ${OPENGL_glu_LIBRARY}
+)
+
+ADD_EXECUTABLE(AppRaytracer
+        Raytracer.cpp
+        main.cpp
+)
+