Beta 1.7

Changes:

• gravel has a chance of dropping loose stones instead of itself
• removed the defunct namespace system, hence eliminating the framerate slowdowns
• implemented a system of movable windows. Won't describe it here, try it out yourself
• the inventory, item selection and ore area info screens are now movable windows
• item selection is now separate from the inventory, and can be accessed by pressing I
• added more splashes