title: Extend maven cargo plugins jvmargs
body: <p>I have a maven project which extends an existing parent project (It's the "standard product" from which my product will be a "Customized product").</p>
  
  <p>The parent declares a <code>org.codehaus.cargo / cargo-maven2-plugin</code> and passes it some VM args under <code>configuration</code> / <code>cargo.jvmargs</code>. Like this:</p>
  
  <pre><code>    &lt;plugin&gt;
        &lt;groupId&gt;org.codehaus.cargo&lt;/groupId&gt;
        &lt;artifactId&gt;cargo-maven2-plugin&lt;/artifactId&gt;
        &lt;version&gt;1.4.18&lt;/version&gt;
        &lt;configuration&gt;
          &lt;container&gt;
            &lt;containerId&gt;tomcat8x&lt;/containerId&gt;
            [...]
            &lt;dependencies&gt;
              [...]
            &lt;/dependencies&gt;
          &lt;/container&gt;
          &lt;configuration&gt;
            &lt;properties&gt;
              &lt;cargo.jvmargs&gt;-ArgA -ArgB -ArgC&lt;/cargo.jvmargs&gt;
            &lt;/properties&gt;
            &lt;configfiles&gt;
              [...]
            &lt;/configfiles&gt;
            &lt;files&gt;
              [...]
            &lt;/files&gt;
          &lt;/configuration&gt;
        &lt;/configuration&gt;
      &lt;/plugin&gt;
  </code></pre>
  
  <p>Now in my custom project, I want to extend these jvm args with one more argument (Let's say -ArgD), so that the args are -ArgA -ArgB -ArgC -ArgD. I don't want to override the entire plugin only to do this one little change.</p>
  
  <p>I know that I can specify this: <code>cargo:run -Dcargo.jvmargs="-ArgD"</code> but the problem here is: All other args (ArgA, ArgB, ArgC) get overridden/removed, only ArgD will remain. What I need is something like <code>cargo:run -Dcargo.jvmargs="current_cargo.jvmargs + -ArgD"</code>. </p>
  
  <p>Is this possible somehow?</p>