make btHashMap data protected (not private) for easier serialization

move btTriangleInfoMap.h into its own header, into the BulletCollision/CollisionShapes folder
add btTriangleInfoMap pointer to btBvhTriangleMeshShape, so we don't need to use the 'userpointer' anymore
preparation for serialization of btTriangleInfoMap.

See also http://bulletphysics.org/Bullet/phpBB3/viewtopic.php?f=9&t=4603&start=30

Demos/CollisionInterfaceDemo/CollisionInterfaceDemo.cpp

@@ -30,7 +30,7 @@ subject to the following restrictions:
 #include "GlutStuff.h"
 #include "GLDebugDrawer.h"
 
-float yaw=0.f,pitch=0.f,roll=0.f;
+btScalar yaw=0.f,pitch=0.f,roll=0.f;
 const int maxNumObjects = 4;
 const int numObjects = 2;