Task rewards rebalance

[trebidav]

Idea

As the application is community driven, community should be able to give feedback about the Tasks valuation.
Core mechanism to implement this is Rating the task after completion by the assignee who just completed the task.

Rebalance

• A rebalance event will collect all new Ratings and rebalance the base values of the Tasks available.
• A rebalance event is repeated (e.g. every day, every week, after all tasks are done for the day). It can be triggered manually as well.