Tab

Much of the tab page code was based on the navigator page code.

The cache system does work for pages contained in the tab page. Is this something worth implementing? If so, how should I go about doing it?

fixes #59 
You can convert the documentation to [Apple doc](https://github.com/tomaz/appledoc/wiki/appledoc-docs-comments) format. That way it's picked up by cocoadoc.org when we publish it to cocoapods and Xcode recognizes it.

Spoiler, it's not too different from Javadoc:)