DATAJPA-466 - Add support for lazy loading configuration via JPA 2.1 fetch-/loadgraph.

Applied suggestions from code review.
The EntityGraph to use can now be configured on query method level via the new @EntityGraph annotation. The new method JpaQueryMethod#getEntityGraph analyses an @EntityGraph annotation and constructs a new JpaEntityGraph value object that contains the information form the annotation. The new method AbstractJpaQuery#applyEntityGraphConfiguration tries to apply the given EntityGraph configuration if the used JPA persistence provider supports the JPA 2.1 spec.
Changed the class path order such that EclipseLink is now placed before the eclipse dependency. EclipseLink references the JPA 2.1 API and allows us to provide type-safe support for the new JPA 2.1 features.