Add licence
	modified:   README.md
	modified:   src/systemscala/component.scala
	modified:   src/systemscala/event.scala
	modified:   src/systemscala/logger.scala
	modified:   src/systemscala/pipe.scala
	modified:   src/systemscala/signal.scala
	modified:   src/systemscala/simtime.scala
	modified:   src/systemscala/simulate.scala
	modified:   src/systemscala/thread.scala