Conveyor Belts

Added robotic arms! These can move items between belts and inventories. There are also filter robotic arms which can take only the filtered item.
Allow filter conveyor belts output on the back for one of the sides, using a config menu in the block.
Improved placement mechanics. Press R (by default) to toggle placement direction, crouch and tap R to cycle through the belt types (flat, up and down)
Filter conveyor belts and filtered robotic arms no longer consume the filters
Filter conveyor belts and filtered robotic arms can now accept FTB's Item Filters