Merb_has_flash is a plugin for the Merb framework that provides Rails-style
flash.
The ``flash'' provides a way to pass temporary objects between actions.
Anything you place in the flash will be exposed to the very next action
and then cleared out. This is a great way of doing notices and alerts,
such as a create action that sets
flash[:notice] = "Successfully created"
before redirecting to a display action that can then expose the flash
to its template.