Loosen development dependency for cutest
Replace public certificate

The previous certificate was valid until 08-08-2014.
Make the pattern in IRC::Message#match optional
Fix a bug where invalid messages cause IRC::Message.new to raise an exception
Let IRC::Message#match accept String and Numerics
Move IRC::Message#numeric? and IRC::Message#error? to IRC::RFC2812::Message
Fix a bug where IRC::Message#== returns false for another IRC::Message
Fix a bug in IRC::Message#match where the block wasn't called and no pattern was provided
Alter IRC::Message#== to compare raw messages
Remove IRC::RFC2812::Commands#raw
Use String#tr instead of String#gsub in IRC::RFC2812::Prefix