PHP agenda version 2.2.2 released

This is the first release in a rather long time and there are numerous improvements over previous versions of the package. The main feature of this release is the added Guest access which allows users that are not member to view the agenda.
The full list of improvements includes:
- implemented guest access to the agenda
- added a link to return to the day overview
- fixed a bug that makes you log-out after the session expires
- the months in the month overview now center around the current date
- all dates that are displayed are now links to that date
- removed unneeded checkboxes
- reminders are now only visible if they are enabled in the script
- removed the check for updates feature
- created and ant build script to quickly build releases
- fixed a display bug for IE 6.0