[ticket/10776] Fixed errors in docs/README.html.

PHPBB3-10776
[ticket/10776] Fixed a couple language changes in docs/README.html.

PHPBB3-10776
[ticket/10772] Use forum specific style for trigger_error

PHPBB3-10772
[ticket/10772] Functional tests for forum style

PHPBB3-10772
[ticket/10772] Remove unnecessary comment

PHPBB3-10772
[ticket/11579] Add basic set of unit tests for validate_data()

This currently includes tests for the string, num, date, match, and
language iso validation functions.

PHPBB3-11579
[ticket/11579] Add remaining unit tests for validate_data functions

This now includes tests for usernames, passwords, emails, and jabber
addresses. A few small changes had to be applied to phpbb_mock_cache
and phpbb_mock_user in order to incorporate needed methods.

PHPBB3-11579
[ticket/11579] Remove unnecessary globals from validate_password()

The globals $db and $user are not used in that function.

PHPBB3-11579
[ticket/11579] Move tests into seperate files depending on needed fixture

PHPBB3-11579
[ticket/8319] Prepend Board URL to LOCAL_URL links to prevent abuse

The description says:
"The URL must be relative to the topic page and cannot contain a server name
or protocol."
We now enforce this and will add a new token with the current behaviour back.

PHPBB3-8319
[ticket/8319] Add new token RELATIVE_URL to allow foreign relative URL parts

PHPBB3-8319
[ticket/8319] Update BBCodes that currently use the LOCAL_URL tag on update

To fix http://tracker.phpbb.com/browse/PHPBB3-8319 we changed the
second_pass_replace value, so that needs updating for existing ones.

PHPBB3-8319
[ticket/8319] Add explanation for RELATIVE_URL and update LOCAL_URL

The explanation now states that links are prefixed with the board URL.

PHPBB3-8319
[ticket/11579] Use test case helper class and use assert prefix for method

PHPBB3-11579
[ticket/11579] Move simple tests into seperate files

PHPBB3-11579
[ticket/11579] Rework calls to validate_data_helper

PHPBB3-11579
[ticket/11579] Add missing commas to validate_username_test

PHPBB3-11579
[ticket/11579] Do not extend validate_data_helper

PHPBB3-11579
[ticket/11579] Add method for validating emails for valid MX and mark as slow

A method for setting up the prerequisities also has been added in order to
reduce the amount of necessary code.

PHPBB3-11579
[ticket/11543] Add unit tests for obtain_guest_count()

PHPBB3-11543