Update component.json for 'component' support

Add 'styles' property to component.json to play nice with 'component'.

'Component' is another component package manager.
See: https://github.com/component/component
Language and comment style

* Make consistent use of tense in code comments.
* Update the comment style to match a more common convention.
* Remove an unintentional newline.
Fix cursor style for disabled button `input`

The Android 4.0.* work around - `html input[type="button"]` - requires
the addition of `html` to the selector for disabled inputs, otherwise
disabled button inputs still have the `pointer` cursor.
Add `main` element to HTML5 display definitions

The HTML Working Draft has added `main` as a new element.
Update CHANGELOG