Color palette support

I added this functionality at a basic level to your app. It reads a palette color file (for now only in .less format) and in the color preview panel shows the name of the hovered color of it matches one of the colors in the palette.

It's useful for developers who work with screen files from designers and want detect color names used on a png. Or vice versa.
![screen shot 2013-06-04 at 4 24 11 pm](https://f.cloud.github.com/assets/234060/606008/828b7a6c-cd22-11e2-8466-c377172f34d8.png)