copyright comments.
rename packages clausf.backgammon > net.f05fk.backgammon.
corrected test case: Board is immutable and move() returns a new
instance.
moved get first move implementation from DummyBot to StandardRules.
replaced int positions with enum Position.
refactored Player: toString()/fromString().
Die: comparable; Die and Dice: fromString().
Movement: fromString().
renamed MoveTest to MovingTest
BoardTest: removed static from test test methods.
Position: fromString().
Move: fromString().
implemented RandomBot.
Dice: bugfix toString().
DieTest: translated message to English.