Enhancements:

• Add support for PostgreSQL data type uuid.

Bugfixes:

• After an error message, calls to the foreign server result in this error:

  error connecting to Oracle: OCITransStart failed to start a transaction
  ORA-01453: SET TRANSACTION must be first statement of transaction
  

  The problem is that the previous transaction was not closed. This used to go unnoticed, the problem now becomes manifest because we explicitly start a serializable transaction. Per reports from Keith Fiske and Bruno Voigt.