- lights are by default off (what was I thinking?!?)
- setters return "me" reference by default, for easier code obfuscation:
foo = aircraft.light.new("/foo").prop().switch(1); :-)
- a few mebmers renamed; light.set() -> light.switch(); nodes are named *N
to avoid collisions and to show relations (switch() <-> switchN)
- yet more (too much?) documentation
- light class added (for lights and other pulsing/blinking objects)
- fixed and improved documentation
- all property args may be path strings or nodes
- existing nodes aren't overwritten any more
- better naming of class vars (for outside access)
Tested with the bo105 (which I fully ported to use aircraft.nas) and
the fokker70 (which are the only aircraft using the new classes :-)
