Description:
------------
As said in the link below, is_callable() will always return TRUE if _call() is 
defined.

Maybe it should simply not, or maybe whe should have another magic method like : 
__methodexist($name), that return TRUE if a method could be called by __call().



http://www.php.net/manual/fr/function.is-callable.php#49879

Test script:
---------------
<?php


class TestMe {
	public function __call($name, $args) {

	}

	public function bug($function) {
		return is_callable(array($this, $function));
	}

	public function iExist() {

	}
}


$test = new TestMe();
var_dump($test->bug('iExist'));
var_dump($test->bug('iDont'));


Expected result:
----------------
bool(true)
bool(false)


Actual result:
--------------
bool(true)
bool(true)