Hookup scheduling and notifcation pipeline. Alter the project layout
to use modern Chrome extension practices.
Keep track of the tabId so we can reference the correct script.
Add basic script injection, which will control actions on the actual page.
Add a hook to clear timers if the page is closed or changed.
Close popup after submitting a timer request.
Add ping functionality so multiple managers are not injected accidentally.
Implement the Google Music connector.