Default the data serialization directory to a subdir in the installation directory.

Modify the installer so that it alters the xwoot_working_dir value in xwoot.properties file in the webapp to point to a subdir in the installation directory specied at install time.

If XWoot is not installed using the installer, but just by dropping the xwootApp.war in a container, xwoot_working_dir should be by default empty and force the user to select one.

See: http://izpack.org/documentation/user-input.html