Refactor element upgrade and insertion/removal watching into a unified observer system
rename some methods in Observer.js, improve comments
document.register only triggers document-wide upgrade when called after initial load is complete, pre-load-complete registrations are processed in one step on load-complete
Merge branch 'master' of https://github.com/toolkitchen/CustomElements into observer
Merge commit '2c80460' into observer
Merge pull request #21 from toolkitchen/observer

Merge Observer Refactor