Real turn management

* Ending a turn swaps control to the next team
Basic AI that ends its turn after 5 seconds
Exiting mouse hover from a character restores to the previous character
Disable en turn button on AI turns
Rename DungeonActor#switch_control_to_next_playable_character

* Now named #switch_control_to_next_player_playable_character
* Makes it explicit this method is used for switching control for the player only
Display the current playing team on top
Focus on first played character by AI
Merge pull request #83 from rafaelgonzalez/add-ennemy-ai

Turns and enemy AI