Changes

Enhancing projection tests and fixing projection result handling:
- Improved test coverage for both derived queries and native queries with projections (differentiating projected interfaces with @Value annotation from others without it)
- Fixed PartTreeStalactiteProjection to return hierarchical Map structure instead of Object[] for proper Spring Data unmarshalling (see buildHierarchicMap() utility method)
 (commit: 9f6d9a3)

Splitting windowing logic into pieces to make it reusable (not yet finished) in NativeQuery
 (commit: b57c827)

Applying split windowing logic to the default query case. Still requires to be applied to NativeQuery
 (commit: f94629a)

Reworking SqlNativeRepositoryQuery execution algorithm to make it appear a pattern of projection + paging + query execution. Still require some more work.
Enhancing NativeQuery paging support.
 (commit: 001c1a2)

Code cleanup of previous commit: simplifying SqlNativeRepositoryQuery execution code, class renaming and deletion.
 (commit: 9b3acc9)

Moving reducer classes to a more suitable package
 (commit: 045195f)

Adding support for @BeanQueries and projection, pagination and windowing by sharing code with SqlNativeRepositoryQuery and pushing up some abstraction to AbstractRepositoryQuery.
 (commit: cac7206)

Reviewing pagination to make it thread-safe: Limit object was shared. Still some work to make all thread-safe.
 (commit: 5c7865b)