Changes since ZConfig 2.1:

- More documentation has been written.

- Added a timedelta datatype function; the input is the same as for
  the time-interval datatype, but the resulting value is a
  datetime.timedelta object.

- Make sure keys specified as attributes of the <default> element are
  converted by the appropriate key type, and are re-checked for
  derived sections.

- Refactored the ZConfig.components.logger schema components so that a
  schema can import just one of the "eventlog" or "logger" sections if
  desired.  This can be helpful to avoid naming conflicts.

- Added a reopen() method to the logger factories.

- Always use an absolute pathname when opening a FileHandler.

- A fix to the logger 'format' key to allow the %(process)d expansion variable
  that the logging package supports.

- A new timedelta built-in datatype was added.  Similar to time-interval
  except that it returns a datetime.timedelta object instead.

Changes since ZConfig 2.0:

- Removed compatibility with Python 2.1 and 2.2.

- Schema components must really be in Python packages; the directory
  search has been modified to perform an import to locate the package
  rather than incorrectly implementing the search algorithm.

- The default objects use for section values now provide a method
  getSectionAttributes(); this returns a list of all the attributes of
  the section object which store configuration-defined data (including
  information derived from the schema).

- Default information can now be included in a schema for <key
  name="+"> and <multikey name="+"> by using <default key="...">.

- More documentation has been added to discuss schema extension.

- Support for a Unicode-free Python has been fixed.

- Derived section types now inherit the datatype of the base type if
  no datatype is identified explicitly.

- Derived section types can now override the keytype instead of always
  inheriting from their base type.

- <import package='...'/> makes use of the current prefix if the
  package name begins witha dot.

- Added two standard datatypes:  dotted-name and dotted-suffix.

- Added two standard schema components: ZConfig.components.basic and
  ZConfig.components.logger.

Changes since ZConfig 1.0:

- Configurations can import additional schema components using a new
  "%import" directive; this can be used to integrate 3rd-party
  components into an application.

- Schemas may be extended using a new "extends" attribute on the
  <schema> element.

- Better error messages when elements in a schema definition are
  improperly nested.

- The "zconfig" script can now simply verify that a schema definition
  is valid, if that's all that's needed.
