DATAJPA-551 - Add support for limiting the query result in the query derivation mechanism.

We now support to restrict the results of a query method via the "Top" or "First" keyword within the method name.

Note that this feature requires the PR https://github.com/spring-projects/spring-data-commons/pull/85 to be applied to SD CMNS first!

Original pull request: #96.
DATAJPA-551 - Add support for limiting the query result in the query derivation mechanism.

Changed SlicedExecution to only try to fetch an additional record if the given query is not restricted via a query limit.
Added test cases for Paged and Sliced query executions.