Made the gripper action stall
Made the joint angle and cartesian actions have a stall option. Parameterized many of the previously hard-coded parameters
Made node recover in the event of loss of comms with the arm, except it will still crash if the loss happens while an action is in progress. Reason for that is still unknown.
Made the node not crash even when the arm is disconnected during an action
Made the tf trees have a prefix to allow for multiple arms with their own tf trees