[General] Wiki tweaks

[Jared Rhine]

Last week, we turned of "BlackListPlugin" because it was misbehaving 
badly; this was announced here.  The root cause (a style of Apache 
configuration) has been addressed and the BlackListPlugin re-enabled. 
I'm keeping an eye on it, but please let us know if you see anything 
like the problems we saw last Thursday with being blocked.

Also, I'd heard reports that sessions/logins/authentication were very 
short; that should now be addressed as well.

Thanks.  Sorry for the hassle.

-- Jared