Iterative pre-commit reviews

On a pre-commit review, we need a way to make it iterative.

Here is a common scenario:

1) The developper creates a Pre-commit review
2) The Reviewer insert a comment in a file to adjust something in the code
3) The developper gets notified, and makes the correction.

Now, how this developper sends then update to Crucible so the reviewer can
get notified and complete the review?

Right now, we can click the "Add a patch from workspace changes to the Review."

The problem is that it duplicates the file in the review, wich can become very
unreadable on multiple files review/multiple comments and changes.

There should be a way to group the same files together and show only the latest one in the review window, with something like a [+] on left to expand and see other versions.