Added named colors. And some minor changes.

The major feature of this pull request is a set of named colours. Now you can use, for example, `.bck.lightblue` class to set the `background-color: #add8e6;` property or `.text.color.lightblue` to set the equivalent text color.

The next feature is `.hoverable` class. If you add one to a table, its rows will be colored with `#dedede` color on hover. 

*Note:* one needs to be refactored to use color, depending on the theme colors or table row color.

And the last API change is removed top padding for `<secion>` tag. This padding added some uglyness if you have used it so i just thought *"Hey! I do not want to override this rule any time i use this framework! I don't need others to see this though!"* and removed it:

![screen1](https://f.cloud.github.com/assets/137882/907467/dd5c4c8c-fd3d-11e2-90b4-dc0c02c86f24.jpg)

Other change is `README` additions related to the `package.json` file. I created one to make the setup process more... Smooth.