Fixed bug on Field skipping in QueryByExample management in JPQLQueryEngine
fixed a shutdown issue
Merge branch 'master' of github.com:romaframework/persistence-datanucleus
fixed bug on jpql query engine: backslash was not quoted properly
Added support to subqueries (JPQL)

example:
QueryByFilter query = new QueryByFilter(MainClass.class);
QueryByFilter subQuery = new QueryByFilter(OtherClass.class);
subQuery.addProjection("otherClassId");
query.addItem("attributeOfTypeOtherClass", QueryOperator.NOT_IN,
subquery);

ATTENTION: in the subquery it is MANDATORY to declare a projection; if
the expected result of the subquery is OtherClass, use the primary key
field for the projection
fixed JPQL Query Engine to correctly manage fetch groups
update datanucleus version.
updated datanucles version
fix for new datanucleus version.
Merge branch 'master' of github.com:romaframework/persistence-datanucleus
Merge branch 'master' into mvn

Conflicts:
	ivy.xml
	src/org/romaframework/aspect/persistence/datanucleus/jdo/JPQLQueryEngine.java