For a tag to declare that it accepts dynamic attributes, it must implement
this interface. The entry for the tag in the Tag Library Descriptor must
also be configured to indicate dynamic attributes are accepted.
For any attribute that is not declared in the Tag Library Descriptor for
this tag, instead of getting an error at translation time, the
setDynamicAttribute() method is called, with the name and
value of the attribute. It is the responsibility of the tag to
remember the names and values of the dynamic attributes.