Add option to configure the graphic setting

[BBortfeldt]

The application should provide a settings dialog or options menu to configure the graphic settings.

Currently the settings are hard-coded in the main-method. jME has a default dialog to configure the graphics settings which can be called every time the application starts. There should be a mechanism to save these settings so the dialog won't open every time and a possibility to change these settings during runtime.

• analyse what settings dialog to use (jME or custom implementation)
• add mechanism to save the graphic settings
• implement useful behavior
  • open settings first time starting the application or when no settings are detected
  • allow settings to be changed during runtime