MVStore: the ObjectDataType comparison method was incorrect if one key was Serializable and the other was of a common class.

MVStore: temporary tables from result sets could survive re-opening a database, which could result in a ClassCastException.

MVStore: temporary tables from result sets could survive re-opening a database, which could result in a ClassCastException.

MVStore: temporary tables from result sets could survive re-opening a database, which could result in a ClassCastException.

Undo change to make the tests run again. Sooner or later the MultiDimension tool will be removed as now we have spatial indexes.

fix NPE when backing up and there is a ".mv.db" file lying around that we do not currently have open

reduce synchronization bottleneck in processing date/time values by using a ThreadLocal for the cached Calendar object

Spatial Index: adjust costs so we do not use the spatial index if the query does not contain an intersects operator.

MVStore: unique indexes that were created later on did not work correctly if there were over 5000 rows in the table.

For Windows, database URLs of the form "jdbc:h2:/test" where considered relative and did not work unless the system property "h2.implicitRelativePath" was used.

getTimeTry() was never being passed a null timezone, so don't check for that. Rather check if the timezone is still the default, so we can use the local cached Calendar.