Vote budgets

In our current solution (Discourse based), we limit users to 20 votes each. They can retract their votes to "re-spend" them and when a request is implemented that vote still shows on the request, but they get it back into their pool of votes. In effect, they can only vote on 20 not-yet-complete features at any one time.

This is very important to us as it forces our users to vote for their top 20. If they don't know what they top 20 requests are, how are we meant to!