Options not respected for ID Fields in XML Mapping Driver

Same bug of the YAML driver, see: http://www.doctrine-project.org/jira/browse/DDC-2661
Options not respected for ID Fields in XML Mapping Driver (XSD update)

XSD update.

The same bug of the yaml driver: see http://www.doctrine-project.org/jira/browse/DDC-2661
[DDC-2732] Add tests for XML id options fix.
Merge branch 'DDC-2732'