add a helper method to turn the Collection<Edit> into a patch string?

[jstrachan]

I couldn't figure out how to take the results of BlobUtils.diff() and use the DiffFormatter from JGit to create a human readable textual representation of the differences.

Any chance of adding a helper method maybe? Rather than using BlobUtils.diff() I ended up snaffling some code from gitblit for now:
https://github.com/hawtio/hawtio/blob/master/hawtio-git/src/main/java/io/hawt/git/GitFacade.java#L301