Core Plus 2.4.7b7

	* Changed the behaviour of filters.  They now accept "0" as a valid value and will display
	  the filter system with it if a "" value is present.  This enables filters that act on a
	  boolean property to function correctly.
	* Changed the behaviour of Form::addModel and getModel methods.  The form system now saves
	  the model in a local variable and makes that exact model available on the next pageload.
	* Removed some legacy code from the Form system pertaining to the PageModel.  That model now
	  handles the logic internally.
	* Fix in the Model system to not try to propagate keys up to the parent of a linked model.
	* Better enforcing Model and the DMI default values.  ex: enum field types now require one
	  of the options to be set as default if null is set to false.
	* Minor performance tweaks in the PageModel.
	* Moved the "components_load_complete" hook to be fired after the postincludes instead of
	  before.  This ensures that smarty and some other systems are available.