Some improvements to ResultSetPeeking to minimize the change of getting out of sync with the underlying result set

Fixes a bug in XmlInputStaX where row number was incremented prematurely in hasNext(), should be incremented in next() to align with all other result set implementations

git-svn-id: https://svn.apache.org/repos/asf/jena/trunk@1465137 13f79535-47bb-0310-9956-ffa450edef68