[ticket/10854] sql server drop default constraint when dropping column

drops default columns with T-SQL before attempting drop column to
avoids sql exception.  This is a huge annoyance in UMIL scripts running
under sql server.
[ticket/10949] Converted AJAX coding standards to new guidelines.

Basically, moved parentheses to same line and changed variable names to
camel case.

PHPBB3-10949
[ticket/11015] Make DBAL classes autoloadable

PHPBB3-11015

This allows us to just create the object without having to include the
driver first. However, it also means that users must specify the full
class name in config.php
[ticket/11015] Add BC files for the drivers

PHPBB3-11015
Merge branch 'develop' into ticket/11015

* develop:
  [ticket/11012] Fix php_ext change in mock_extension_manager
  [ticket/11012] Normalize $phpEx member vars to $php_ext
  [ticket/11002] Use translating option to rename the Etc/GMT options

Conflicts:
	phpBB/includes/extension/manager.php
[ticket/11015] Correctly set sql_layer in driver base class

PHPBB3-11015
[ticket/11015] Fix connection manager db driver selection

PHPBB3-11015
[ticket/11015] Fix db connection type hint in lock_db

PHPBB3-11015
[ticket/11015] Fix configuration for travis

PHPBB3-11015
[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