Updated the LevelSelector.cs class and LevelSelectSceneGUITest.unity to use a much less hard coded style. Will now be able to handle any amount of levels we have, so long as they are in the build settings. Scrolls up and down only using three buttons, rather than one for each level.

Joint effort between Karl and I.

Signed-off-by: Hobo42 <taiteryan@gmail.com>
Minor changes to LevelSelector.cs, just changed how things incremented and decremented. Nothing big.

Signed-off-by: Hobo42 <taiteryan@gmail.com>
Merge pull request #127 from Hobo42/master

LevelSelector.cs update for scrolling list