Added support for user defined java and game parameters

TODO: GUI support, but i dont know how to use JavaFX

Properties are defined in LauncherSettings
They are passed through to GameStarter from ApplicationController and properly added to the list
I have run it and it works
Currently it has "-XX:+ParNewGC -XX:+ConcMarkSweepGC" as default java parameters

Improvement:
I have a Core i7 4700HQ and a GT755M in my laptop and i allocated 2GB ram
Uber Graphics (everything maxed out) 1080p
- with java params: runs at a *cinematic* 30 fps
- without: runs at a (slideshow) 10 fps as well as eventually hitting the ram limit and thus having frequent lag spikes due to GC pauses
`USER_JAVA_PARAMETERS_DEFAULT` is private in `LauncherSettings` so you cannot access it here.