Add logic to convert mummy/order values to long when parsing XHTML metadata.
Since we've been converting the mummy/order property (defined in Artifact) in HTML from a string to a long on the fly in AbstractPageMummifier.toLong(). We've had a TODO to switch to some general conversion system such as Ploop, and eventually we may want to still do that. Or not.
In we implemented special parsing for default-namespace properties in a certain form, but in that ticket we also anticipated eventually being able load ontology definitions for individual namespaces. For example we might have an ontology defined for the mummy/ namespace, indicating that mummy/order should be an urf-Number, so that it would automatically be converted to a long once, up-front when reading the document, and not on-the-fly as we use the value. There is already a placeholder for such logic in AbstractMummifier.parseMetadataPropertyValue().
So in the meantime we can add special-case logic for mummy/order to convert it to a long. The special logic will take the place of a facility for defining the mummy/ ontology in some declarative manner until we implement that.
This is relatively important to do so that the output site description can have the correct mummy/order type.
We may or may not keep the toLong() code and consider adding the general conversion facility.
During implementation of this ticket we need to add another ticket for the general declarative ontology definition facility, as well as a ticket for adding a general conversion facility (if we still want to do that; we may decide that with an ontology definition facility it's better to be strict and convert up-front).
Added ticket for the ontology definition facility.