Hmmm... that would be better for now. However, it will be really awesome if could achieve that in some point of time.
Yes. Exactly, making themes git repository and thus using git to maintain versions (i.e. each save reflecting a commit), should enable functionality very similar to Google Docs. Since we are making theme folders git folders, we can also have external repository as remotes allowing admins to maintain the theme elsewhere. In fact, git revert/pull/fetch/push could serve us to implement a pretty advanced versioning system. This should be the primary and most useful deliverable of the project.
Here is google doc link to it -http://bit.ly/2HVGUJE. Its a rough draft for now, and I will add mockups and more details by tonight. I hope to add some code references also well in time. Thanks for sharing me the relevant packages, and your gsoc project would serve me an inspiration.
I have set-up a normal Plone 5 application, and I am not sure whether it is the development instance. I will go through the instruction and build it.
I will complete it by tonight.