Maven property ${appengine.app.version} get interpolated

[mosofsky-netbase]

The pom.xml files for the modules seem to be missing a <configuration> section for this plugin:

 <plugin>
 <groupId>org.apache.maven.plugins</groupId>
 <artifactId>maven-war-plugin</artifactId>
 <version>2.3</version>
 </plugin>

That's preventing a substitution of ${appengine.app.version} from happening in appengine-web.xml. I've described the problem in more detail here: http://stackoverflow.com/questions/27475714/why-doesnt-maven-property-appengine-app-version-get-interpolated-in-multi-mo/27475715

What I notice is that the version number is just hard coded in appengine-web.xml: https://github.com/GoogleCloudPlatform/appengine-modules-sample-java/blob/master/appengine-modules-shardedcounter/src/main/webapp/WEB-INF/appengine-web.xml:

<appengine-web-app xmlns="http://appengine.google.com/ns/1.0">
 <application>yet-another-sharded-counter</application>
 <version>1</version>
 <threadsafe>true</threadsafe>

 <module>shardedcounter</module>

</appengine-web-app>

I'd like to propose to you the solution I've documented on stackoverflow: http://stackoverflow.com/a/27475715/2848676