Magento - Log all events on action

mage.php

<?php

# change method in mage.php

public static function dispatchEvent($name, array $data = array())
{
    Mage::log('Event: ' . $name); //not using Mage::log, as 
    //file_put_contents('/tmp/test.log','Dispatching '. $name. "\n",FILE_APPEND); //poor man's log
    Varien_Profiler::start('DISPATCH EVENT:'.$name);
    $result = self::app()->dispatchEvent($name, $data);
    #$result = self::registry('events')->dispatch($name, $data);
    Varien_Profiler::stop('DISPATCH EVENT:'.$name);
    return $result;
}