Decision system - v0.3.8

v0.3.8 changelog:

• base for a new decision system
  • currently only used for creating and joining parties, other decisions will be migrated to this system in later versions
  • creating and joining parties now happens through events
  • you get to see the reasons for and against a decision
  • if you have enough influence over the adventurer, you can steer them in a different direction
• new menu background
• continued style migration