title: Repository for maven plugin dependency defined in pom is not used
body: <p>I switched to a SNAPSHOT version of a plugin I use, and declared the corresponding snapshot repository in the POM like this:</p>
  
  <pre class="lang-xml prettyprint-override"><code>&lt;project&gt;
      &lt;!-- ... --&gt;
  
      &lt;build&gt;
          &lt;pluginManagement&gt;
              &lt;plugins&gt;
                  &lt;plugin&gt;
                      &lt;groupId&gt;org.apache.openjpa&lt;/groupId&gt;
                      &lt;artifactId&gt;openjpa-maven-plugin&lt;/artifactId&gt;
                      &lt;version&gt;2.3.0-SNAPSHOT&lt;/version&gt;
                  &lt;/plugin&gt;
              &lt;/plugins&gt;
          &lt;/pluginManagement&gt;
      &lt;/build&gt;
      &lt;repositories&gt;
          &lt;repository&gt;
              &lt;id&gt;apache.snapshots&lt;/id&gt;
              &lt;name&gt;Apache Snapshot Repository&lt;/name&gt;
              &lt;url&gt;http://repository.apache.org/snapshots&lt;/url&gt;
              &lt;releases&gt;
                  &lt;enabled&gt;false&lt;/enabled&gt;
              &lt;/releases&gt;
          &lt;/repository&gt;
      &lt;/repositories&gt;
  &lt;/project&gt;
  </code></pre>
  
  <p>Now Maven keeps complaining about not being able to download the plugin from our corporate repository (which does not mirror anything on the internet) - it just ignores the repository defined in the POM.</p>