This allows to not use the internal game state directly from client
code.

* Implement move artifact action
* Fix widget update memory leak
  * update the highlights not during on each frame
  * do not update the unchanged label of a button
* Allow to exit the game by pressing 'q'
* Implement some cards from the magic set
* Improve permanent formatting
* Some tweaks to UnitAI code

* Add more TODOs
* Implement permanents granting more spawn tiles

* fix a lot of target and action bugs
* check target selection before adding it to the prompt
* use the store view for stores on the map
* fix card highlighting in CardGrid
* Only prompt for Upkeep-/DiscardActions if appropriate
* Add helper for areaEffects granting new FullActions
* Add Target() helper selecting the first target to the Action interface
* Fix BuyAction and DiscardAction targets
* Remember the stores a player has seen

* implement most of the kraken cards
* unify permanent marks
* add state based actions hook for card implementations

adding area effects and hooks for permanents entering and leaving tiles

* Introduce new callback for leaving a pile without beeing dropped
* Fix equipment contrsuctor
* Implement attack inheritance