MultiThreaded Demo:

- fixing various race conditions throughout (usage of static vars, etc)
 - addition of a few lightweight mutexes (which are compiled out by default)
 - slight code rearrangement in discreteDynamicsWorld to facilitate multithreading
 - PoolAllocator::allocate() can now be called when pool is full without
     crashing (null pointer returned)
 - PoolAllocator allocate and freeMemory, are OPTIONALLY threadsafe
     (default is un-threadsafe)
 - CollisionDispatcher no longer checks if the pool allocator is full
     before calling allocate(), instead it just calls allocate() and
     checks if the return is null -- this avoids a race condition
 - SequentialImpulseConstraintSolver OPTIONALLY uses different logic in
     getOrInitSolverBody() to avoid a race condition with kinematic bodies
 - addition of 2 classes which together allow simulation islands to be run
   in parallel:
    - btSimulationIslandManagerMt
    - btDiscreteDynamicsWorldMt
 - MultiThreadedDemo example in the example browser demonstrating use of
   OpenMP, Microsoft PPL, and Intel TBB
 - use multithreading for other demos
 - benchmark demo: add parallel raycasting

examples/OpenGLWindow/SimpleOpenGL3App.cpp

@@ -352,7 +352,7 @@ void SimpleOpenGL3App::drawText3D( const char* txt, float worldPosX, float world
 }
 
 
-void SimpleOpenGL3App::drawText( const char* txt, int posXi, int posYi)
+void SimpleOpenGL3App::drawText( const char* txt, int posXi, int posYi, float size)
 {
 
 	float posX = (float)posXi;
@@ -374,7 +374,7 @@ void SimpleOpenGL3App::drawText( const char* txt, int posXi, int posYi)
 	{
 		bool measureOnly = false;
 
-		float fontSize= 64;//512;//128;
+		float fontSize= 64*size;//512;//128;
 		sth_draw_text(m_data->m_fontStash,
                     m_data->m_droidRegular,fontSize,posX,posY,
 					txt,&dx, this->m_instancingRenderer->getScreenWidth(),