Investigate issues with private channels

[adsr]

#68
#66

[jcolson]

#66 is a pita ... as i delete channels all the time and use a bouncer (quassel) --- but due to this bug it never /parts the channel on delete and so the bouncer 'recreates' the channel everytime i connect (doing a /join) because it never sees the part as it should ;-) I got it working earlier, but have since started using the latest trunk code (the speedy reconnecting fixes you made are FANTASTIC!)