Import GORA-199v2.patch
GORA-199 New bugfixes

- Add missing src/test/conf/gora.properties to avoid NullPointerException
- Avoid crash in MongoDBQuery if missing fields
- Start support of UNION (very early stage)
- Fix behavior of schemaExists / schemaCreate
Fix mapping for tests.
Use MongoMapping to convert Schema fieldname to Mongo Document fieldname