New option dsm.skip

[romani]

Please provide a skip option similar to:

http://mojo.codehaus.org/findbugs-maven-plugin/check-mojo.html#skip
http://mojo.codehaus.org/animal-sniffer-maven-plugin/check-mojo.html#skip
http://maven.apache.org/plugins/maven-checkstyle-plugin/checkstyle-mojo.html#skip
http://maven.apache.org/plugins/maven-pmd-plugin/check-mojo.html#skip

@parameter(property="dsm.skip", defaultValue="false")
private boolean skip;

That way one can enable the plugin by default and selectively not execute it
via:

mvn clean install -dsm.skip=true

or a profile:

<profile>
    <id>fast_build</id>
    <properties>
        <dsm.skip>true</dsm.skip>
    </properties>
</profile>

mvn clean install -P fast_build