Fully delete user (purge them) from the system

[Robert Lyon]

Currently when we call 'delete_user()' we delete most of the user's data but we leave some bits behind, like forum posts and obfuscate the user's email address in the usr table.

But it would also be useful to add a 'purge' option to delete_user() function so that we could delete all info about a user so it was like they never existed, including all files in the dataroot etc

So in lib/user.php the function delete_user($userid) would become function delete_user($userid, $purge = false)

And we'd add just before the db_commit() an if($purge) { } section to deal with full cleanup.

[Kristina Hoeppner (kris-hoeppner)]

We'll need to be a bit careful about forum posts though I think. In contrast to a person's portfolio and files contained within it, forum posts are often part of a conversation and deleting them could destroy the conversation. I wonder, if that may need to be an option when the user is deleted. If forum posts are to be deleted, then there should be a placeholder post saying that the post was deleted rather than making it vanish altogether (like we already do when an admin deletes a post that is not the last in a conversation).