Introduce lifecycle callbacks

* Enables initial filterText.
* Enables use of "match" class for styling instead of awkward "not-match".
Introduce Shadow DOM
Introduce <content> element
Introduce HTML templates
Introduce style encapsulation
Introduce Shadow DOM styling
Introduce HTML Imports
Introduce nested imports/component re-use

* Explain that the bower_components folder came from running `bower install basic-list-box
* The one exception to the `just a link rel tag needed to import a component` is the platform.js file.`
Introduce inheritance