CSS Color Plugin

Plugin to add a nice float when hovering a color in css syntax that shows the color. Supports all color notations (short and long hex value, rgb(a), hsl(a) and valid CSS color names. In order for this to work a CSS value definition needed to be added, and the import definition has been moved inside of the value definition.

Additionally I added punctuation and string definitions to the `css.selector.inside` which ins't required for this plugin but is something that I felt was missing. (Also the CSS Extra seems to be adding these definitions but there is no CSS in place for them?)

The CSS Color definitions (`css.value.inside.color`) because outside of this plugin being able to detect all the css color names seems a bit useless.

Some screenshots:
![hex](https://cloud.githubusercontent.com/assets/7327050/4364792/bef87638-42a3-11e4-9e78-c6709e60719d.png "CSS Highlight with Hex color float.")
CSS Highlight with Hex color float.

![rgba](https://cloud.githubusercontent.com/assets/7327050/4364794/cf7f540e-42a3-11e4-834f-a26a2fa8d3c9.png "CSS Highlight with rgba float.")
CSS Highlight with rgba float.