Area Shields

check every 5 second to keep the game from coming to a crawl. -If a unit comes within range that isn't already enhanced, the PSU adds it to the table, adds a shield to that unit and bumps up it's own energy usage. -Units that move out of range within the next check, have the shield destroyed, the unit removed from the PSU's table and the energy cost of the PSU lowered. -If a unit is destoyed, it will be removed from the PSU's table upon the next check. (Simple and clean) -If the PSU is destroyed, all units held with the PSU's table have their shields destroyed.