Fixes for broadphase/paircache determinism.

Revert definition for ATTRIBUTE_ALIGNED16, and try to force sizeof(btSolverConstraint) by using unions with btScalar, for non-btScalar data types.
Use btAssert and not assert.
Don't access btAlignedObjectArray elements, for zero sets

Demos/OpenGL/GL_ShapeDrawer.cpp

@@ -296,7 +296,7 @@ void GL_ShapeDrawer::drawCylinder(float radius,float halfHeight, int upAxis)
 		break;
 	default:
 		{
-			assert(0);
+			btAssert(0);
 		}
 
 	}