Use this to dynamically register
postfilters to run templates
through after they are compiled. See template postfilters for
more information on how to setup a postfiltering function.
The php-function callback function can be either
a string containing the function name
an array of the form
array(&$object, $method) with
&$object being a reference to an
object and $method being a string
containing the method-name
an array of the form
array(&$class, $method) with
$class being a classname and
$method being a class method of that
class.
