Merge pull request #318 from sorvell/master

Corrects document.importNode, fixes #317
importNode needs to traverse the tree
Merge pull request #321 from arv/document-import-node

importNode needs to traverse the tree
Implement inserAdjacentHTML
Merge pull request #322 from arv/insert-adjacent-html

Implement inserAdjacentHTML
Fix outerHTML setter so that mutation observers are notified
Merge pull request #323 from arv/outer-html-mutation-observer

Fix outerHTML setter so that mutation observers are notified
Unwrap if needed for the reference node of insertBefore
Add work around for Firefox bug related to window methods
Merge pull request #326 from arv/firefox-window-workaround

Add work around for Firefox bug related to window methods
Use FocusEvent for testing for constructable events instead
README: add :host() 1-level nested parentheses limitation. Fixes https://github.com/Polymer/docs/issues/197
Use emulated dispatchEvent for EventTarget.prototype.dispatchEvent
Merge pull request #324 from arv/unwrap-if-needed

Unwrap if needed for the reference node in insertBefore
Merge pull request #329 from arv/event-propagation

Use emulated dispatchEvent for EventTarget.prototype.dispatchEvent
Merge pull request #325 from arv/event-constructors

Use FocusEvent for testing for constructable events instead
new FocusEvent fails in Safari
Merge pull request #330 from arv/focus-event-init-bug

new FocusEvent fails in Safari