vaadin 6.7.1 and GWT 2.3.x

I use vaadin
to develop my client application, in the release notes it is told vaadin 6.7.1 depends on
GWT 2.3.x
lib. However I just downloaded it and overwrote the vaadin6.7.1.jar in the folder:\WebContent\WEB-INF\lib, and in Eclipse IDE added GWT 2.3.x related jar files, it is okay to compile the code and the app works as well in Browser+Tomcat after my manual creating the war for my application and copied to the webapps of Tomcat home directory.

So my question is where the GWT jar files are utilized at runtime, I didn’t see anything related to GWT jar files in the war package.

GWT jars are
used at runtime, they are used at widgetset-generation time.

I believe that, if you are using the Eclipse Vaadin plugin, then you don’t need to explicitly do anything - the Eclipse Plugin will download and use the appropriate GWT libraries when building.