Change return type of Channel::GetUsers() to reference from pointer as it is never NULL
Rename UserMembList to Channel::MemberMap, switch all code to use it
Remove typedef UserMembCIter, use Channel::MemberMap::const_iterator instead
Remove typedef UserMembIter, use Channel::MemberMap::iterator instead

Remove the now unused UserMembList typedef too
Rename UserChanList to User::ChanList, remove UCListIter