Add the old Bullet 2.x obsolete demos, and CMake buildsystem files, and gradually move them to newer Bullet 3.x structure

Use statically linked freeglut, instead of dynamic glut for the obsolete Bullet 2.x demos
Add the 'reset' method to b3GpuDynamicsWorld, and use it in the BasicGpuDemo (pretty slow in debug mode, use release mode)
Don't crash in btCollisionWorld, if there is no collision dispatcher

ObsoleteDemos/ConstraintDemo/CMakeLists.txt

@@ -0,0 +1,52 @@
+# 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(
+${BULLET_PHYSICS_SOURCE_DIR}/src 
+../OpenGL
+${BULLET_PHYSICS_SOURCE_DIR}/Extras/Serialize/BulletFileLoader
+${BULLET_PHYSICS_SOURCE_DIR}/Extras/Serialize/BulletWorldImporter
+)
+
+
+IF (USE_GLUT)
+	LINK_LIBRARIES(
+		OpenGLSupport BulletWorldImporter BulletDynamics  BulletCollision LinearMath  BulletFileLoader  ${GLUT_glut_LIBRARY} ${OPENGL_gl_LIBRARY} ${OPENGL_glu_LIBRARY}
+	)
+
+	ADD_EXECUTABLE(AppConstraintDemo
+			ConstraintDemo.cpp
+			ConstraintDemo.h
+			main.cpp
+	)
+ELSE (USE_GLUT)
+	LINK_LIBRARIES(
+		OpenGLSupport BulletWorldImporter BulletDynamics  BulletCollision LinearMath BulletFileLoader ${OPENGL_gl_LIBRARY} ${OPENGL_glu_LIBRARY}
+	)
+
+	ADD_EXECUTABLE(AppConstraintDemo
+		WIN32
+		../OpenGL/Win32AppMain.cpp
+		Win32ConstraintDemo.cpp
+		ConstraintDemo.cpp
+		ConstraintDemo.h
+	)
+ENDIF (USE_GLUT)
+
+
+
+IF (INTERNAL_ADD_POSTFIX_EXECUTABLE_NAMES)
+			SET_TARGET_PROPERTIES(AppConstraintDemo PROPERTIES  DEBUG_POSTFIX "_Debug")
+			SET_TARGET_PROPERTIES(AppConstraintDemo PROPERTIES  MINSIZEREL_POSTFIX "_MinsizeRel")
+			SET_TARGET_PROPERTIES(AppConstraintDemo PROPERTIES  RELWITHDEBINFO_POSTFIX "_RelWithDebugInfo")
+ENDIF(INTERNAL_ADD_POSTFIX_EXECUTABLE_NAMES)