Map icons now have a constant size independent of zoom level
Galaxy Map now displays zone properties when clicking on a zone
Zone generator now uses half of nebula density, means smaller and more varied zones
Stations will refuse docking to entities with insufficient clearance
Added MPL license headers
SectorRenderer renders entities in sector, manages particle systems for ship thrusters
Thrusters apply torque based on orientation and position relative to ship center of mass
GameManager controls the player ship's thrusters
Player can dock with station if they are near
Game Context was creating an empty OrbitalEntity for every planet; this was an ugly hack so I refactored it, as well as refactoring some object references to GUIDs as they should be
Ship locomotion now accounts for tangential velocity, slows down properly with terminal phase separated into velocity matching behavior
Tech tree properties panel visualizes parents and children correctly
