Add support to ARQ/SPARQL for more XSD datatypes and related operations.

Possibilities to add to ARQ:
See http://www.w3.org/TR/xmlschema11-2/#built-in-datatypes

xsd:dateTimeStamp
Derived from dateTime by requiring the timezone

xsd:dayTimeDuration
No year or month fields,
Only day, hour, minute, or seconds fields.

xsd:yearMonthDuration
Only year or month fields,
Derived from duration – no day, hour, minute, or seconds fields.

These durations are totally order. Also related arithmetic operations on xsd:dateTime

xsd:time

xsd:precisionDecimal
See http://www.w3.org/TR/xsd-precisionDecimal/