Major update (see further description)

- Added ```indexToPosition``` in Board
- Added ```getFieldAtPosition``` in Board
- Added ```move``` on all axis in Board
- Added ```getDisabled``` function in Field
- Added ```turn``` function in Manspel to switch players and trigger the ```turn``` event
- Added ```number``` property to Player

- Changed disabled fields generation code
- Minor change in for-loop in ```fillPlayerFields```: variable collision
- JSLinted all files