Improved attribute handling
More realistic distinction between IDL attributes and Content attributes AKA HTML properties and attributes, such as htmlFor vs for, className vs class. The HTML output by html-element no longer reflects any arbitrary property into attributes. See #34 for more details.
Dependency updates:
- require at least Node.js 4.2LTS (should have happened in 2.0.0)
- upgrade test runner
tapto latest version