[PATCH] interface_exists()

Hi, today I saw a note left by a person in the documentation on php.net about the lack of function named interface_exists(). Currently there is class_exists() which returns true always when the name is a declared class or a known interface. However an interface is not a class, some will say that it is a pure abstract class - that's true but the name is different and we already have abstract classes. In addition classes and interfaces are differentiated by get_declared_classes() and get_declared_interfaces(). There is a small BC in the case since the patch also makes class_exists() to return false when the name is a name of a known interface. We are only 2 months from 5.0.0 and this fix inconsitency. The patch is agains 5.1.0-dev but can be easily used against 5.0.2-dev . I will be very happy if it will be accepted and someone with karma commits it. The patch is here : http://hristov.com/andrey/projects/php_stuff/patches/interface_exists.patch.txt Thanks, Andrey