Expose the gwt.coverage flag in the gwt-maven-plugin

I want to generate code coverage reports for a GWT project. The GWT compiler can be passed a list of files it will instrument, but this is not convenient in my case. I'd rather be able to give a list of patterns and turn on/off instrumentation using maven profiles.

Typical usage:

    <plugin>
        <groupId>org.codehaus.mojo</groupId>
        <artifactId>gwt-maven-plugin</artifactId>
        <configuration>
            <coverage>
                <enabled>true</enabled>
                <scanDependencies>false</scanDependencies>
                <includes>
                    <include>com/myproject/client/**/*.java</include>
                </includes>
                <excludes>
                    <exclude>**/notneeded/**</exclude>
                </excludes>
            </coverage>
        </configuration>
    </plugin>

Please note that I'm rather new to Maven plugins so this may not be perfect (although it works nicely for me).