[Changes for 0.15 - Mar 8, 2003]
* New - properties beginning with '.' are now sticky to the entry.
* New - merge function to merge two Data::Hierarchy objects.
[Changes for 0.13 - Nov 4, 2003]
* New - get_single and store_single.
* Fix - get_* now return cloned hash to avoid being modified directly.
[Changes for 0.12 - Oct 6, 2003]
* New - Find descendents with a rule.
* Fix - cleanup useless entries after store and store_recursively
[Changes for 0.11 - Sep 26, 2003]
* Fix an obvious edge case.
[Changes for 0.10 - Sep 26, 2003]
Initial release.