Fixed two bugs in BoardState.

isAccessibleForTank now adheres to the javadoc:"Checks whether the tank may take a given position" so we are checking if the position is within the board and if it is not occupied by some other tank.

There was also a bug in toString method of the BoardState - fromTop/fromLeft were mixed up and it resulted in rotated board without all tanks
Changed BoardDefinition to value object. Removed FromStringBoardDefinition, BoardBuilder static method fromASCII now creates new instance of BoardDefinition based on passed string.

Removed BoardDefinitionAdapter class - logic was moved to GameRunnerFactory.
Formatting
Made Engine as parameter to GameRunnerFactory
Merge pull request #25 from Adebski/dto-to-value-object

Dto to value object