Posted version 2.5.2 of the plugin to the ZC software moderators.

What changed v2.5.2:

- Removed modifications from core files and used the notifier/observer system instead for ZC 1.5.5. Specifically the autoloader system.
- Replaced the mootools javascript with software that works with ZC 1.5.5.
- Removed changes from template files that did not get incorporated into ZC 1.5.5.
- Added text to identify that the delivery date is optional/required.
Once accepted it will be available for download from the ZC forum from here.