Data redundancy/dependencies

  1. User.alliance is copied to all his planets
  2. User.skill_tree is copied to all his planets
  3. User.point_stats is summed up from all his planets
  4. User.colonies[i].army_str is calculated per planet from units and ships
  5. User.homeplanet.army_str is calculated for homeplanet from units and ships
  6. User.current_research is copied from researching planet (only 1 planet can research at same time)