stub issue: commit title always "created dataset"

[ramfox]

when we go to edit a dataset from the dataset page & click "edit", we populate all the dataset info into the editor. This also populates the commit, with the commit of the previous version. We currently have no way of editing the commit, and the previous commit always gets sent over to the backend for the save. This means the commit title is always the same, if you submit on the frontend.

There is talk of making a person add a commit whenever they click save, in which case this will no longer be an issue, but perhaps a quick fix is not letting the previous commit copy over into the editor dataset.