Huge cleanup

Items sorted in correct order.
Some items no longer used deleted.
[KeyMapping] category added.
Some items added.
Comments added.

Question #1 : Why some items are located in strange places ? >> See line #3 and line #70.

Question #2 : Is it possible to translate the scrolling text in "Credits" ?
Merge pull request #116 from vnctdj/patch-2

Huge cleanup