Camera movement and small updates

- Camera movement is implemented. See the txt in Drive for detailed
explanation.
- Added Level1-Bigger scene with 3 extra rows and 1 extra column for
movement testing boundaries.
- Updated 3 lines in Attack class which for example checked if an unit
gameobject is not null, while the tile class has a method HasUnit()
which already checks that for you. Or getting a tile from a
UnitGameObject via transform.parent.gameobject.getcomponent<tile>()
instead of unitgameobject.tile.
- Updated the check for the donebutton for correct finger usage
(lol...).
- Updated the position and scale of the gamebar in order to fit the full
camera screen.