Use Merge/Diff Interface when autoformatting

"Auto-correct" now brings up the Merge/Diff panel, as talked about in #10 and #1...

![auto-correct-merging](https://cloud.githubusercontent.com/assets/314997/5591854/7687dd06-91ce-11e4-8e0a-8382a8ba8554.gif)

What do you think about this workflow?