RFR (JAXP): 8033980 : Xerces Update: datatype XMLGregorianCalendarImpl and DurationImpl

[huizhe wang]

Hi,

This is an update from Xerces for two datatype classes 
XMLGregorianCalendarImpl and DurationImpl. For details, please refer to:
https://bugs.openjdk.java.net/browse/JDK-8033980

webrevs: http://cr.openjdk.java.net/~joehw/jdk9/8033980/webrev/

Tests included for: 1243, 1416, 1097 (Note that JDK did not have this bug)

No test:
1343: remove unused code

Existing tests: JAXP SQE and Unit tests passed.

Thanks,
Joe