Modifications to sync/welcome page

This is related to #15 and possibly #12.

This commit cleans up how local vs. sync options are figured out on startup.

Now, when the install event fires for chrome_update nothing will happen. Install and Update logic has changed, so this needs to be beta tested for approval.

Also, included download font for forcing a sync of the URL (chrome.storage.sync won't immediately sync if you're offline and go online). See http://fontawesome.io for font details.