Cliff-walk problem finished
1. Removed all vicon code
2. Tidied the directory structure a bit
   -Put all servo_controller stuff in arm_controller
   -Expanded 'unified' directory contents to 1 step below
3. Apart from cliff-walk specific code, added CONVGCHK_GAP
   -Convergence check is only done once in 'CONVGCHK_GAP' times