Merge pull request #9652 from lightsofapollo/improve-error-handling

Bug 867748 - Error recovery from account settings (mostly for oauth2)
Conflicts:

	apps/calendar/js/views/advanced_settings.js
	apps/calendar/js/views/modify_account.js
	apps/calendar/style/modify_account_view.css
	apps/calendar/test/unit/view_test.js