run GUI on main thread for Mac OSX/__APPLE__, due to OS limitation

add b3CreateInProcessPhysicsServerAndConnectMainThread to test.c

examples/SharedMemory/SharedMemoryInProcessPhysicsC_API.h

@@ -11,6 +11,11 @@ extern "C" {
 
 ///think more about naming. The b3ConnectPhysicsLoopback
 b3PhysicsClientHandle b3CreateInProcessPhysicsServerAndConnect(int argc, char* argv[]);
+
+b3PhysicsClientHandle b3CreateInProcessPhysicsServerAndConnectMainThread(int argc, char* argv[]);
+
+    
+    
     
 #ifdef __cplusplus
 }