* xmlschemas.c: Fixed facet errors to be channelled back for
  union type members; facet-validation will stop now on the
  first error. Reported by GUY Fabrice to the mailing-list.
* xmlschemastypes.c: Changed to ignore lengh-related facet
  validation for QNames and NOTATIONs as proposed by the
  schema people.
* test/schemas/union2* result/schemas/union2*: Added
  regression tests for union types (by GUY Fabrice).