This addresses #497 and allows the admins to disable notifications
through the admin panel. Might be used by those relying on clients using
the API instead.
Once merged it will fix#497.
* Currently no GUI, use DB access to change the row entry
* Upgraded Database table `accounts` with upgrade SQL
* Updated `admin` field to `is_admin` as boolean
* Modified pages, classes, templates to support is_admin and is_locked
Addresses #147
* Adding new SQL upgrade for notifications
* Added support for per user notification settings
* Added account_id to notifications table
* Added new notification_settings table
* Added new account page: notifications
Addresses #144