messaging 6.x-4.0-beta4

Since beta3:
- Added views support for messaging_simple, by joshuajabbour, #791694
- Added some extenstions to Message class: get_method_params()
- Simplified and improved message sending workflow.
- Fixed multiple upgrade issues and bugs: #787304, #786844, #790984, #792850, #790226, #792756
New features:
- Revamped admin pages and options. Better settings, queue, log, etc
- Improved filtering. Added a new settings page for filters and new filter/format options
- Improved Destinations, dropping method field, a destination is now an address.
- Added hook_messaging('address types') for send methods to share address information
- Extended templates with language and translations
- Major OOP rework: Message, Destination, Send_Method
- Reworked messaging_simple, now it uses its own table
- Support for Anonymous destinations / subscriptions.
- Reorganized modules: new template module, moved debug module to notifications_extra, etc..
- Implemented 7.x like API for static variables,
- API and storage improvements for upcoming multilingual support.