Version 0.9.0:
- Added method set_parameter, which allows to change the value
  of existing configuration parameters.
- Added path_prefix, which enables you to define a prefix that
  will be put in front of all XPath expressions.
- Added method close, which terminates the reloader thread.
- Included module Observable, so it is possible now to add
  observers, that will be notified, if a configuration file
  has changed.
- Added method store, which stores the current configuration
  into a file.
- Added method to_s, which returns the current configuration
  as an XML string.
- Renamed many methods, i.e. removed postfix "_parameter".
  The old method names still work, but will probably be removed
  in the future.
- Restructured unit tests and put many test cases into
  separate files.
- Added and improved documentation: Added sections 'Observing
  a Configuration File' and 'Changing and Storing a
  Configuration File.'.

Version 0.8.0:
- Handling of attributes is configurable now. They will be
  expanded by get_parameters, if the user wants them to.
- [] is an alias for get_parameter now.
- get_parameter_array was added by Nigel Ball.
- Changed method names to Ruby style. The old method names
  still work, but will be removed in the future.
- 'ruby install.rb config' prints a warning now, if REXML
  is not installed (pre-config.rb was added).
- Added and improved documentation.

Version 0.6.0:
- Values for true and false are configurable now.
- Default value for getBooleanParameter is nil now.
- Buggy handling of empty elements in method nodeToText
  was fixed by Sandra Silcot.
- Added and improved documentation.

Version 0.5.0:
- Using Minero Aoki's setup package now.

Version 0.4.0:
- Added mechanism for automatic reloading.
- Path separator is configurable now.

Version 0.3.0:
- Added support for substitution of environment variables.
- Enhanced Rdoc comments.

Version 0.2.0:
- First working release.

