Add piwik header to all .php files

[matt]

All Piwik PHP files should contain the following header:

<?php
/**
 * Piwik - Open source web analytics
 * 
 * @link http://piwik.org
 * @license http://www.gnu.org/licenses/gpl-3.0.html Gpl v3 or later
 * @version $Id: $
 * 
 */

[vipsoft]

I'd like to suggest adding an explicit copyright statement.

[vipsoft]

(In [1259]) Fixes #524 - add standard Piwik header to .php files in core & plugins, with the exception of those in core/Updates/.

[vipsoft]

Use attached script to identify files without the required header:

find core -name '*.php' -exec perl hasheader.pl {} \;
find plugins -name '*.php' -exec perl hasheader.pl {} \;

[vipsoft]

(In [1698]) refs #524 - add standard header