[ticket/11103] The start of an all-encompassing notifications system

This system will take input from various systems to store notifications
and send notifications to users all in one nice extendable system.

This system should act something like the notifications system on
other social networking sites (in that, there is a single location where
a user can see all of their notifications for various events).

PHPBB3-11103
[ticket/11103] Working on the add/update notifications functions

Some cleanup and additional commenting as well

PHPBB3-11103
[ticket/11103] Output the notifications to the template

For now, just dumping the notifications in the header.

PHPBB3-11103
[ticket/11103] Private Message type notification

Also cleanup

PHPBB3-11103
[ticket/11103] Add tables to the database updater and installer

PHPBB3-11103
[ticket/11103] Forgot a constant

PHPBB3-11103
[ticket/11103] Work on the pm type and email method

PHPBB3-11103
[ticket/11103] Jabber notification method base

PHPBB3-11103
[ticket/11103] Fixing some db columns that were of the incorrect type

PHPBB3-11103
[ticket/11103] Some fixes for the email method

PHPBB3-11103
[ticket/11103] Order notifications properly

PHPBB3-11103
[ticket/11103] Full url function

PHPBB3-11103
[ticket/11103] Move banned user checking to email method

This will make sure banned users are never sent notification emails

PHPBB3-11103
Merge branch 'develop' of git://github.com/phpbb/phpbb3 into ticket/11103
Merge branch 'ticket/11103' of github.com:EXreaction/phpbb3 into ticket/11103
[ticket/11103] The service now handles all user loading itself

Delete pm notifications when pms are deleted

PHPBB3-11103
[ticket/11103] General notification email template.

PHPBB3-11103
[ticket/11103] Do not initialize the notifications in common.php

DIC initializes it when it is needed.

PHPBB3-11103
[ticket/11103] Post notifications

PHPBB3-11103
[ticket/11103] Use the language system, topic notifications

PHPBB3-11103