DATAJPA-481 - Upgraded to Spring Framework 3.2.4.

Upgraded to Spring Data Build 1.3.0.BUILD-SNAPSHOT to benefit from upgrade to Spring Framework 3.2.4.

Made the sample mapping file in test folder a valid XML document to prevent Eclipse from marking it as error.
DATAJPA-405 - Guard against null predicates on query creation.

We now only call CriteriaQuery.where(…) if the predicate we handle is a non-null value. Adapted Jpa(Count)QueryCreator accordingly.