Use mymodule parameter for module definition.
This was also helpful in revealing places where the code relied on the global environment.

Changed amavis-controller.lua to use new handle_form() functions found in acf_www-controller.lua instead of the controllerfunctions.lua version and also instead of redirect_to_referrer(). Made corresponding changes to amavis-model.lua to make everything
 work.

Changed amavis-controller.lua to use new handle_form() functions found in acf_www-controller.lua instead of the controllerfunctions.lua version and also instead of redirect_to_referrer(). Made corresponding changes to vmail-model.lua to make everything work.