Option to delete a branch after pull request merge

I'm loving Pull Requests so far – I can definitely see us adopting a 'branch for every story and issue' approach.

However, the downside to that is you will end up with a LOT of branches in Stash. They can be manually removed from a git client (like SourceTree).

What I would like is to have a Pull Request that can optionally delete the branch after the merge. This is a great way of marking that issue/story as completed and merged, because its then removed.

(I appreciate that there is no need from a git point of view to remove the branch, but for a human perspective of having to look at a gigantic list of branches, it is desirable.)

This is somewhat related to STASH-2491 as that relates to using branches for release/issue management.