urlencode query_string for magic auth to make sure GET params make it back
to the originating server
save channel/<channel>/?mid=... plinks with the items
use plinks instead of llinks on network/ and channel/ pages, though not in
mode network-new (network/new and network/search)
fix a bug that made it possible for everyone to access any message from other
channels using channel/<channel>/?mid=...
took out some left-overs from the debugging phase