Log Message:
Update to version 4.2.
This is the last version before adding support for Python 3.x.  Only bug
fixes will be added to this branch.  From the changelog:

Version 4.2
-----------
- The supported Python versions are 2.4 to 2.7.
- PostgreSQL is supported in all versions from 8.3 to 9.5.
- Set a better default for the user option "escaping-funcs".
- Force build to compile with no errors.
- New methods get_parameters() and set_parameters() in the classic interface
  which can be used to get or set run-time parameters.
- New method truncate() in the classic interface that can be used to quickly
  empty a table or a set of tables.
- Fix decimal point handling.
- Add option to return boolean values as bool objects.
- Add option to return money values as string.
- get_tables() does not list information schema tables any more.
- Fix notification handler (Thanks Patrick TJ McPhee).
- Fix a small issue with large objects.
- Minor improvements in the NotificationHandler.
- Converted documentation to Sphinx and added many missing parts.
- The tutorial files have become a chapter in the documentation.
- Greatly improved unit testing, tests run with Python 2.4 to 2.7 again.