ikiwiki/ tips/ user command

After battling with the oneliners in inside dot ikiwiki, I have expanded them into a full script (current snapshot, latest).

It has three commands:

- `list`: just list the users as a TSV (tab-separated list)
- `dump`: use `Data::Dumper` to dump the entire database, as done in the oneliners
- `delete`: delete the given user, or interactively approve all users one by one

It's kind of rough right now, but it helped me deal with the emailauth bypasses account_creation_password problem, as a crude anti-spam protection. In particular, it "vendors" the lock mechanisms because `lockwiki` and `unlockwiki` are not exported by the `IkiWiki` module, which is unfortunate.

It could be improved significantly: for example, the `delete` command could use a "time" argument to review only the accounts created after a certain date, instead of reviewing the entire list each time. I just couldn't be bothered with the date parsing.

I would be happy to see this command land in ikiwiki itself, under a GPL-2+ or whatever open license. -- anarcat