Revert "lets try something else for osx"

This reverts commit 6f722eab1cd2b4b1550f4ab21f37e1d2281a526b.
Revert "try to get .app working"

This reverts commit e0ac63638c479f5d2b763efa8349a914be05a672.
Start work on OS X specific UI features

* Create the dock icon
* Set Menu/dock title when launching Minecraft applet
* Add "native" fullscreen button to Minecraft applet window.