DDC-126 - Make Query, NativeQuery Fluent-Interfaces for all their set Methods, renamed setExpireQueryCache() and setExpireResultCache() to expireQueryCache() and expireResultCache(). Updated UPGRADE_TO_2_0 document accordingly.

[2.0] Various necessary fixes and adjustments for oracle as well as fixes for better handling of temporal types. Closed #2452.

[2.0] Moved code between Query and AbstractQuery. Added first NativeQuery implementation. Hydration work and code movements for discriminator column usage. Started implementing Single Table Inheritance.