Correct css shimming to match native; extendee styles are shimmed IFF there's a <shadow> element.
shim styles with similar specificity rules as native: extendors override extendees
TemplateInstances -> TemplateBinding
Use native ShadowDOM by default only when it's available unprefixed. This helps ensure a more complete native implementation in Chrome.
Allow users to opt in to native ShadowDOM even when a fully supported version is not available via ?shadow=native.
test: update karma config
test: ignore global leaks
update tests
moved library coop tests from polymer
test: add karma-ie-launcher