The build was not properly excluding the launcher from the compiler jar.
And the compiler and ant jar were actually being created twice.
Added a static start() method very similar to main() that doesn't do a `System.exit()`
Now using the new `start()` method in CeylonTool which doesn do `System.exit()`
Added a static `run()` utility method similar to `main()` but slightly easier to use from code
Now re-using the CeylonClassLoader if it's already available in the Thread's context