Aded Config class to hold, read and write current game configuration.
Added FileIO class which is a wrapper for reading/writing to files on SD card and reading raw assets.
Modified AndroidGame to contain and initialize those classes.
Added settings loading on startup.
Modified MainMenuScreen sound button to change configuration. Added saving configuration at application closing.
Moved a lot of files to engine package.
Merge branch 'master' of https://github.com/jczarnowski/SpaceShooter

Conflicts:
	src/com/jcf/spaceshooter/engine/ShuttleController.java
	src/com/jcf/spaceshooter/screen/GameScreen.java
Updated references to old package (current-engine).
Added AddHighScore blank method to Config class.