Lab2 javafx

**Ready for review**

Added bindings support with [javafx](http://docs.oracle.com/javase/8/javafx/get-started-tutorial/jfx-overview.htm#JFXST784) library. Also changed project layout due to [java plugin](http://www.gradle.org/docs/current/userguide/java_plugin.html) update (added `java` and `resources` folders).
@bobylkov-f It's low-level [binding API](https://docs.oracle.com/javafx/2/binding/jfxpub-binding.htm). If you need to create some custom (complicated) behavior, you can link interesting properties through it. For this case, "input" values are linked together, so notifications are received if any property updates.