Feature request: diff merging

[felzix]

I'm using jsondiff to reduce how much I'm sending to clients. My current scheme returns a list of diffs since the last time the client requested the state. It would be better if it sent one diff with all changes together, in case redundancies.

As a side note: it would be nice if there were a way to turn the result of a diff back into a diff. In other words, turn the strings representing symbols back into symbols. This way I can internally represent state as dictionaries without having to serialize them to a json blob to apply the diff.