Refactoring JavaFX Builds & Sources

[Richard Bair]

OK, I've split the generation script into two pieces -- one is closed and one is open. The open one contains all the logic for creating a "javafx" directory sibling of rt and copying sources etc into it, in the new directory layout.

It doesn't build yet unless jfxrt.jar is on the class path. If you manage to get the right version of the file it should build -- modulo the printing build break that is awaiting the next weekly build.

Richard