Allow wikis to be redirected when deleting

[edg2s]

Fixes #171

[edg2s]

Thoughts @MatmaRex?

[MatmaRex]

I think this could be confusing, e.g. if you're discussing different versions of a patch and then a demo of an older version gets redirected to the newer one.

Maybe we should allow defining a message instead, or at least add an interstitial rather than actually redirect?

[edg2s]

Changed to a redirect message instead.

[MatmaRex]

If you still want to get this done, I guess it should use the database for storage now…