notifications 6.x-1.0-rc1

- Added support for updating sending methods from messaging.
- Digesting options per interval and support for digesting plug-ins.
- New digest format, 'Long', to print out the whole event.
- Reworked message templating and digesting, added tests.
- Performance improvements for taxonomy subscriptions (and groups).
- Improved query builder to support fields with array values.
- Added field information in hook_notifications() for contentg and tags.
- Allow aditional parameters for notifications_lite, by Frando, #304220
- Disable notifications on content events, by Darren Fergusson, #331061