Add support for Pascal Neis' Changeset Visualization app

[arch0345]

As explained in #600, it would be nice for this option to only show up for changesets from the past month

Closes #688, closes #600

[mxxcon]

Any chance this could get some attention? Seems like a relatively simple addition with great benefit to reviewers..

[dantecatalfamo]

I'd like to see this as well