DatePicker - ADH08

http://hondou.homedns.org/pukiwiki/pukiwiki.php?Wicket%20%C6%FC%C9%D5%A4%CE%C6%FE%CE%CF%CA%E4%BD%F5#p7508811
そうそう。見つからないなーと思ったらそういうことか。

Wicket1.3になるときに分割されたらしい 
http://cwiki.apache.org/WICKET/migrate-13.html#Migrate-1.3-DatePicker 

The DatePicker component has been removed from the wicket-extensions package,
as it conflicts with the Apache license.

There are two options for migration:

   * A drop-in replacement (same component) provided by Wicket Stuff.
   * A new date picker based on the Yahoo UI library,
     which is available in the wicket-datetime package.
     Find it under wicket.extensions.yui.calendar.DateField
     (see also DateTimeField and CalendarPopup for other useful components).

pom.xmlに下記を追加。

<dependency>
      <groupId>org.apache.wicket</groupId>
      <artifactId>wicket-datetime</artifactId>
      <version>${wicket.version}</version>
</dependency>