Adding global message ignore to channel options

http://pokemon-online.eu/forums/showthread.php?18585-Option-to-quot-opt-out-quot-of-Global-Messages&p=254082#post254082 stole this idea from Lamp's post :x Basically helps with less active channels from getting clogged up with global message spam, though the user still gets the choice in the end, in case they like look at them for w/e reason