Add onInstalled and onRestarted events
Switch onBootstrapLoaded to a Cordova sticky event
Make chrome spec not depend on cordova on desktop
Delay bootstrap start until plugins finish init
Moved Drive file id caching to chrome.storage.

Also removed file ids from the cache when files are removed.
Added remote-to-local deletion syncing.

Also added a couple of function comments.
Refactored Drive id caching functions.
Added caching for the next change id.

Change retrievals from Drive are no longer duplicated across multiple runs.