BumpThread updates the parent thread from a given post.

DeleteOldThreads deletes any thread that's fallen from the index.

DeletePost returns an error that should be checked in the handler.

GetIndex returns every post that started a thread.

GetPost returns a post given its ID.

GetThread returns every post that belong to a thread.

SavePost returns a struct with the ID and delete code of the inserted post.

UpdatePost returns an error that should be checked in the handler.