1. Get the language from the wicket component rather then from the
session. This way, wicket components might provide a different language
for the calendar, while the default is still the session's value.

2. Added a close-if-id-matches. Helpful for closing open calendars
attached to components that get replaced by AJAX

3. Small changes to build - encoding, java target version, src jar,
dependency to wicket 1.4.22 (as 1.4 branch is now discontinued) +
version bumped to match wicket version.