Gameplay

Changed namespace Blaido to Gameplay, added basic methods to gameplay
classes
New cards; NumberCard, HealCard, BoltCard

Added all the original cards; numbercard (values from 2 to 7(?)), bolt
card (removes the last given card), healcard(negates bolt, also
numbercard with value 1)
Removed tools folder/namespace, Gameplay tested on gamescreen

All cards functionality tested (draw situation, bolt, mirror, heal),
TODO: Check win/lose conditions (if player uses a card and his pile
value is still  lower than opponents, he will lose <- not implemented
yet)
Win-lose conditions checked