Tasks Extension

[kronosapiens]

Part of the ongoing "task types" project.

Slack conversations describing the spec can be found here and here.

Essentially, create a "managed" variant of the task in which the manager can make unilateral changes to the task, and which omits the rate/reveal flow, but still records the task data on-chain.

An important feature is that described in #79, where a claimDelay is included in task finalization (not implemented for native Tasks).

Another feature is that described in #165, which describes how the manager's creation stake is returned only after a timeout period.

Another feature is that described in #104: In order to create a task, the manager must possess sufficient reputation and must stake a number of Colony Tokens proportional to the amount of reputation within the domain. This stake is used to discourage spam, and provide a mechanism whereby the manager can be punished for bad behaviour.