JENA-406 NullPointerException using xsd:anySimpleType

Fixes:
1/ core - check before starting the two slot sliding window walking the type tree in XSDDatatype.getFoundingType().
2/ TDB protects itself against throwables when attempting to inline nodes.

git-svn-id: https://svn.apache.org/repos/asf/jena/trunk@1450979 13f79535-47bb-0310-9956-ffa450edef68