Allow other users to edit plugins.

Currently the only person who can edit a plugin is its creator.

I though about this because the halftime and doubletime plugins are flawed. There are fixed plugins floating around the forum somewhere but I can never remember where to find them. The original creator is apparently MIA and has done nothing to fix these. If others could edit a plugin page, they could at least add a link to a better working version with an explanation of why someone would chose that one over the original.

I don't see this causing any problems because those who write programs around here seem to talk to one another and avoid stepping on each others' toes.