#869 - DBAL-1293 - Correcting tests around the invalid date/time formats to use `setExpectedException`

Add conversion exception when date and time type convertToDatabaseValue methods are passed non-null values that are not DateTime instances.

DBAL-26 - Fix nasty bug with null values in Date, DateTime, DateTimeTz and Time fields introduced with the DBAL-22 fix

DBAL-22 - Throw ConversionException if DateTime, Time, Date, DateTimeTz, Array or Object conversions from the Database to PHP fail

DDC-179 - Use ! modifier in Date Format to reset all non-date parts to zero unix timestamp values, i.e. H:i:s => '00:00:00' always