DATAJPA-505 - Projections for basic primitive arrays should use SingleEntityExecution.

We now execute a query as a SingleEntityExecution if the return-type of the particular query-method is an basic char[],Character[], byte[], Byte[].
Previously we tried to do an CollectionExecution which didn't return all elements of the actual result (e.g. the byte[]).

Although EclipseLink and Hibernate support the use of array elements in projections OpenJPA seems not to. Filed https://issues.apache.org/jira/browse/OPENJPA-2484 to track the issue. Since OpenJPA prevents the bootstrap of the whole test suite I had to comment the query method + tests out. Tested Hibernate / EclipseLink by temporarily excluding all OpenJPA tests from the test-suite.

Original pull request: #71.