fixed issue with cable puzzle screens not being set as topmost
bug fixes

added a "leavescene" callback to the scene scripts, use this to remove any permanent screens when changing scenes
fixes for jump system, blinking light will not start until route is plotted
stopped afterburner working when ship is off
cleared some old stuff from the reactor
Merge branch 'testing' of https://github.com/lhsbikeshed/MainGame into testing