Patch 1.6.6

Added precursor shipyard and science station that can be recovered using the system survey manager. The recovered shipyard can be used to do retrofits even if the system is not yet colonized but cannot build new ships until do so. The science station if recovered provides +10 research bonus. Fixed colony fleets losing their colonization target after loading a saved game. The survey menu now shows player assets in system. Fixed engine buff and de-buffs causing issues with ship movement.