1. db needs to be closed\n 2. remove DB_CLOSE_DELAY\n 3. test threads need to join before continuing

Clients that are still on Java 7 and can not use OffsetDateTime need a
way to bind TimestampWithTimeZone. Unfortunately TimestampWithTimeZone
can currently not be used as a bind parameter
The obvious way to bind TimestampWithTimeZone would be to use
PreparedStatement.setObject(int, Object). This does not work because
DataTye#convertTo currently does not check for TimestampWithTimeZone.

This commit fixes this by adding a check and conversion in
DataTye#convertTo and also adding a unit test.

In order to make the doc generation for #476 working I had to fix some
errors in existing files. These cover

 - lines which are too long
 - incorrect indentation
 - invalid markup
 - missing javadoc

* Custom data types handler

* Updated doc, changelog, dictionary. Fixed review comment.

* Extended the custom types handler interface

* Fixed test

* Fixed review comments

* Added note on ABI stability of the feature to docs