Closing tags converted using Oleg's script.
remove-php-end-tags.py -a .
Trailing newlines added using the following where $ext is file extension.
find . -type f -name "*.$ext" -print | xargs printf "e %s\nw\n" | ed -s;
Extensions: php, css, html, js, xml.
PHPBB3-9556
Since only the SIGNATURE_PREVIEW parameter is evaluated in the templates
<!-- IF SIGNATURE_PREVIEW --> will not allow the signature to be "0".
<!-- IF SIGNATURE_PREVIEW != '' --> however does allow "0".
PHPBB3-9665
