admin supplier/product task list - enhancements

inventory, orders and unordered items dialogs now use delegated events
instead of app events.

Inventory dialog now has a button for adding a product to the product
task list.

The product task list code will now target the product tab instead of
the task list itself IF the product tab is not in focus.
admin - enhancement

In order for the product task list to be 'available' to other
extensions, the task list UL must be present early in the process.  The
product manager interface is now loaded in the background.