now that we require Java1.7

Support more types in getObject

ResultSet#getObject is missing some conversions in table B.4 of the
JDBC specification.

- add support for Blob in getObject
- add support for Clob in getObject
- add support BigInteger <-> BIGINT
- add support java.util.Date <-> TIMESTAMP
- add support java.util.Calendar <-> TIMESTAMP
- add tests for SMALLINT
- add tests for BIGINT

Issue#591 Generated SQL from WITH-CTEs does not include a table ident…

where we are calling getException() and seeing a null value.
Because we access these without synchronization, we need to use volatile.