- fix <activity:subject> generation so we get the profile info (what's available so far)
- use id instead of nickname for group join/leave forms so we can join/leave remote groups
while the rest of the groups UI remains limited to local groups
(plugins are responsible for making sure remote notifications and permission checks are done)
- fix remote notification when joining group through OStatus's remote subscribe form
After fixing the redirect code output, there are a lot of weirdnesses
with e.g. form handling. Try to add explicit redirect codes where
needed -- principly when handling a POST.
