Extend the schema parser toward full structural parity:
- list simple types validate each whitespace-separated item against the item
type and count items for the length facets; union simple types admit a value
valid for any member type. A restriction over a named list or union inherits
its variety.
- Named attribute groups are expanded (transitively) into every complex type
that references them.
- Named model groups are expanded at each xs:group ref, with a cycle guard;
element refs resolve to the referenced global element's declared type,
through a reserved type-table key so forward and recursive refs settle at
validation time.
Named simple types now resolve over repeated passes so they may restrict or
list one another regardless of document order. Simple-type and facet parsing
moves into a sibling XSDSimpleParser to keep each parser within bounds.
Closes#65
Mihaela Mihaljevic
cadc63ba8b