[gNewSense-users] Website user changes

[Brian Brazil]

There have been a number of small changes to user handling on the
website. The first is that users may now only contain letters,
numbers, hyphens, underscores and periods.
I've removed the spaces from all existing usernames, but everything
else was fine.

New users are now checked case-insensitvely to existing users. (danielt).

Finally, all users now have attr permissions on their profile page.

All this means we have freedom to do more exotic stuff with pmwiki in
the future.

Brian