Updated derive.js: Fixed multiple inheritance
Updated derive.js: Fixed multiple inheritance

derive() now properly inherits from prototype's prototypes,
meaning you can do things like derive( Ctor, HTMLElement )
and Ctor's proto will get the full chain (HTMLElement > Element > Node >
EventTarget > Object) functionality.

The annoying drawback of this technique is, that `instanceof` checks for
inherited prototypes will fail (return false). But hey, at least we
inherit the full functionality.

derive( Ctor, Super1, Super2, Super3, ... ) also does work properly now.

jhermsmeier/derive.js