Updates Play Framework to 2.2 RC2
Heavy refactoring in order to support the new Structure.xlx version:
-Some entities are now case classes
-Added several traits in order to simplify the DAOs (PoiDao, FileDao, and so on)
-Refactored DAOs using a more funcional style
-Other minor changes (A lot of them, but to small to be mentioned...)
Refactored Dataset, DataSetDAO and DatasetDAOImpl
Finished ObservationsDAOImpl (Includes a 'temporal" fix)
Merge branch 'enhancement-#1' into web, resolves #1