Feature/npc controller is currently slow

[hallfjonas]

computation time can be limited by setting a time-out

• included a configurable time-out option for the controller
• tried to make the computation more efficient
• I think eventually we need something like A*

future development

• the controller often crashes because it's decisions are too greedy on straight lines
• this PR closes NPC controller is currently slow #45
• we can work on improving performance in a new issue