the required jtidy.jar is only available in the JFix-project:
http://code.google.com/p/jease/source/browse/trunk/JFix/WEB-INF/lib/jtidy.jar
You can use the following link to directly download the jar-file and
put it into your WEB-INF/lib if you need Tidy:
http://jease.googlecode.com/svn/trunk/JFix/WEB-INF/lib/jtidy.jar
As Jease doesn't make use of Tidy so far, I don't distribute the
jar-dependency with Jease to keep the set of required libraries as
small as possible. If you have a use-case for Tidy, please let me
know, so I can reconsider to add jtidy.jar to Jease.
Cheers, Maik