defer document.register until custom extendee is registered
first tests for class registration order
towards using mocha/chai from tools
inoculate element registration to the effects of load order
punt 'async' for 'noscript' because of imports-polyfill timing; remove wait list entries after using them
when using HTMLImports polyfill, defer processing polymer-elements in the main document until HTMLImportsLoaded
disable logging
fix test: need to include noscript where appropriate.
update test
wait for extendors to fully register before registering extendees