Here is one way to get Middlegen to generate the <version> tag content
in the xxx.hbm.xml files.

In the Middlegen GUI, the only choice for "column specialty" is
"property", but we need another choice: "version".  To get around this,
edit the model-prefs.properties file for your application. Find the line
for your version attribute that says something like:

   hibernate.tables.CLAIM.columns.VERSION.columnspecialty=property

and change it to:

   hibernate.tables.CLAIM.columns.VERSION.columnspecialty=version

This is what would happen if you chose "version" from the drop down in
the Middlegen GUI.  Then re-run Middlegen as usual to get the desired
<version> section in your xxx.hbm.xml file(s).