Add "Arm" node

[oversword]

If there is another node to be added it is the Arm node

The arm node would attach to the side of a body node
The arm node would not be a gravity node
The arm node will block rotation of the body if there are nodes in between
The arm node would be able to left click and right click things
The arm node would be able to use tools
The arm node would hold down a left or right button for a number of cycles (to achieve mining)
The arm node would be able to interact with interfaces??