Added Oracle dialect and new key type TriggerIdentity

Because Oracle has no method to return last insertend ID (truly guaranteed), we should use syntax <pre>"INSERT INTO ... RETURNING id INTO :outputParameter" </pre> when creating records in database. For that reason i created new type of key TriggerIdentity (side by side Identity, Guid, Assigned).

Also Oracle does not support Boolean and Guid types out of the box. Some tests had to be rewritten.

Unit test results:
![oracle_test_results](https://f.cloud.github.com/assets/1442281/1063979/090a240c-1301-11e3-85a8-dcba9cdc4182.png)