title: build-helper-maven-plugin goal:regex-property how to access generated property
body: <p>I try to parse version of project into new variable named build-number, i use following plugin</p>
  
  <pre><code>    &lt;plugin&gt;
      &lt;groupId&gt;org.codehaus.mojo&lt;/groupId&gt;
      &lt;artifactId&gt;build-helper-maven-plugin&lt;/artifactId&gt;
      &lt;version&gt;1.7&lt;/version&gt;
      &lt;executions&gt;
          &lt;execution&gt;
              &lt;id&gt;rename-property&lt;/id&gt;
              &lt;goals&gt;
                  &lt;goal&gt;regex-property&lt;/goal&gt;
              &lt;/goals&gt;
              &lt;phase&gt;package&lt;/phase&gt;
              &lt;configuration&gt;
                  &lt;name&gt;build-number&lt;/name&gt;
                  &lt;value&gt;${project.version}&lt;/value&gt;
                  &lt;regex&gt;\.&lt;/regex&gt;
                  &lt;replacement&gt;_&lt;/replacement&gt;
                  &lt;failIfNoMatch&gt;false&lt;/failIfNoMatch&gt;
              &lt;/configuration&gt;
          &lt;/execution&gt;
      &lt;/executions&gt;
  &lt;/plugin&gt;
  </code></pre>
  
  <p>My properties section in pom.xml looks  like this</p>
  
  <pre><code> &lt;modelVersion&gt;4.0.0&lt;/modelVersion&gt;
  
   &lt;groupId&gt;xxx.xxx.xxx&lt;/groupId&gt;
   &lt;artifactId&gt;xxx&lt;/artifactId&gt;
   &lt;version&gt;1.1.2&lt;/version&gt;
   &lt;packaging&gt;rar&lt;/packaging&gt;
  
   &lt;properties&gt;
       &lt;build-number&gt;&lt;/build-number&gt;
   &lt;/properties&gt;
  </code></pre>
  
  <p>My question is how to access this variable, after launch of mvn build i can see</p>
  
  <p>[INFO] --- build-helper-maven-plugin:1.7:regex-property (rename-property) @ xxx---
  [INFO] Setting property 'build-number' to '1_1_2'.</p>