Colorized output for supervisorctl status

How about a sexy new feature for 4.0...? :smile: 

I've long wanted this, because it makes the failed processes stand out from the OK ones in a long list.

![supervisorctl_status_colored](https://cloud.githubusercontent.com/assets/305268/5286368/885a5066-7ad8-11e4-8c76-643db94a266d.png)

I'm toying with the idea of colorizing the entire line rather than just the status. Or maybe the name and the status. Having the name colorized seems nice so that your eyes can just scan the first column. Kind of thinking of not colorizing the rest of the line according to status, because I had an idea of maybe colorizing the uptime if it less than a certain threshold (`startsecs`?) -- this is because we sometimes have processes that repeatedly spin up and die and use a lot of CPU, so it can be very useful sometimes to spot the processes that have the shortest uptime...

@mcdonc and @mnaberez: What do you guys think?

I didn't write tests, but I will add them if you're cool with the feature.

If that's the only concern, I can pull in some color constants.

colorama does something fancier to make colors work in Windows, but we could make that optional.