forums [Suggestion] Post/Edit History.

So, essentially you're asking for a Wiki-style history system for individual posts? I think the use cases for that are quite limited and it would require quite substantial overhaul to the methods used to store posts currently. What I would recommend, however, is checking out the Lazarus Firefox addon which is capable of storing data input into forms (such as post boxes) and recalling text from them. I've found it incredibly useful for recovering data in scenarios which I'd have otherwise lost posts.