Partially refactors acp_board for the new authentication interface.
Leaves some questionable if statements in the file.
Modifies the interface to correctly impletment the acp() method.
Modifies each provider to comply with the above mentioned interface
modification.
PHPBB3-9734
Replaces short tags with long tags.
Fixes the interface to be an interface and not class in the file.
Removes unnecessary include_once from auth.php.
PHPBB-9734
Creates a skeleton for Apache based authentication using the
phpbb_auth_provider_interface named phpbb_auth_provider_apache.
This brings over all code in auth_apache.php verbatim complete with
all global variables currently in use.
PHPBB3-9734