added:
- HALVE IT: new modes: Random and Crazy
- CRICKET / HALVE IT: display number of thrown darts at the end of game

fixed:
- HALVE IT: last possible UNDO in game (and following UNDO) produced wrong score calculation and further errors
- HALVE IT: app crashed on UNDO of first two darts, thrown in game
- main menu: inconsistent text color for statistics und settings buttons