Show yellow when typing blipp at 120 chars for Twitter warning

show yellow when typing if you go over 120 or so characters for ease of Twitter use. if you use the http://is.gd service to make the urls smaller when tweeting, it adds about 17 characters to the post. Twitter allows 140. If the graph that shows up as you blipp turned yellow at 120 characters, you'd know you were running into a Twitter limit.