Hide Guild Recruitment Ads

Just a simple filter function in lua that will hide any guild ads using opening and closing characters such as "<Guildname>" to advertise their guild. For example, someone posting a message like the one below would be filtered out of chat, and you would not see the message appear! You will be able to see your own messages that you post, if they contain "<GuildName>" in them, so don't worry about that. 

"Hello fellow travelers, would you like to join <Pretentious Guild Name>? We're looking for more members to do raiding, pvp, leveling, and crafting!"

This message above would not appear in your chat window, as it would be detected by the filter. Don't worry, messages that use "<" or ">" individually are not going to be accidentally filtered out. For now, this only works for text chat where a "<something>" is found in the message body. If anyone finds this useful, I might expand on this to allow a user to add keywords to ignore/filter out or an enable/disable command. Expect a much quieter Trade channel from now on. 

Messages will be filtered in the following channels:

• All regional channels, such as "/1", "/2", "/3" etc. Also known as "General", "Trade", "Local Defense", including custom channels and more. 
• Say "/s"
• Yell "/y"
• Whisper "/w"