Fix ResultSet.getObject() for BigInteger and remove unneeded check

Minor clean up of DateTimeUtils

Make use of try-with-resources statement

Fix issue #406: Return from ResultSet.getObject not in line with JDBC specification

Fix issue #710: Misleading exception message when INSERT has no value for self referential 'AS' column

Add DataUtils.getMapName()

Add row deletion confirmation to web console

Old behavior can be restored by setting h2.oldResultSetGetObject to true

Assorted minor optimizations

Improve the look of error messages in web console

Allocate less amount of garbage

Fix handling of UUID in Datatype.readValue()