StrategyMovementFixes & added 2 placeholders

I've fixed some minor issues that i have found within the strategy board
movement.
1. when you selected one of your pieces to move but then selected an
opponents piece to move too far away, it would be selected as the piece
to move.
2. When you selected one of your own pieces to attack, your piece
doesn't move but the battle sound is played.
All these bugs have now been fixed to my knowledge. I have also
implemented the 2 other placeholder pieces to each side.