Overhauled Chrome extension

Removed popup
Button automatically refreshes page
Per-page awareness of extension state
Bug fix, template update

Inject content script before all other scripts
Removed unnecessary communication between background and content scripts
Comments for clarity
Merge pull request #6 from TylerEich/chrome-extension

Thanks. Now it works perfectly. I'll update the extension and the README of the project and will let you know when the new version is available in Google Web Store.