Renovation of the power grid

Realizing the AMP plugs don't really work (too much unisolated parts even after using lots of shrink tube, too many loose cables) it redid pretty much all electric power cables in the ship.

• The batteries got nice Tamiya style connectors, and thick (ex-loudspeaker) cables: no exposed contacts, fits only one way (no polarity mix-up).
  
• Groups of luster terminals connected to Tamiya plugs for the batteries now provide 6 slots each for GND and +6V, and 4 slots for +12V (combination of two batteries in a row). The "power busses" connect to the inputs of the three power controllers.
• Luster terminals to connect the power controller output with the engines.
• The bow thruster cable got extended.
• The stern thruster cable got shortened.
• The main engine finally got a cable.

This required some serious 75W and 25W soldering (25W don't heat thick copper cables enough), AMP plug removal, cable cutting, insulation removal, and took me the whole freaking day. I'm happy with the result, though: now I can use the joypad to run the thrusters left/right front/aft, apply power, and steer. Cool!