title: Maven: properties not being substituted
body: <p>I'm using a maven plugin for install4j in my project, located <a href="http://code.google.com/p/maven-install4j/" rel="nofollow noreferrer">here</a>. That plugin lets you pass variables to install4j using the <code>&lt;compilerVariables&gt;</code> section. Here's the relevant section of my pom:</p>
  
  <pre><code>&lt;plugin&gt;
      &lt;groupId&gt;com.google.code.maven-install4j&lt;/groupId&gt;
      &lt;artifactId&gt;maven-install4j-plugin&lt;/artifactId&gt;
      &lt;version&gt;0.1.1&lt;/version&gt;
      &lt;configuration&gt;
          &lt;executable&gt;${devenv.install4jc}&lt;/executable&gt;
          &lt;configFile&gt;${basedir}/newinstaller/ehd.install4j&lt;/configFile&gt;
          &lt;releaseId&gt;${project.version}&lt;/releaseId&gt;
          &lt;attach&gt;false&lt;/attach&gt;
          &lt;skipOnMissingExecutable&gt;false&lt;/skipOnMissingExecutable&gt;
          &lt;compilerVariables&gt;
              &lt;property&gt;
                  &lt;name&gt;m2_home&lt;/name&gt;
                  &lt;value&gt;${settings.localRepository}&lt;/value&gt;
              &lt;/property&gt;
          &lt;/compilerVariables&gt;
      &lt;/configuration&gt;
  &lt;/plugin&gt;
  </code></pre>
  
  <p>The problem is that ${settings.localRepository} is not being substituted with the actual directory when I run the plugin. Here's the command line script that install4j is generating:</p>
  
  <pre><code>[INFO] Running the following command for install4j compile: /bin/sh -c /home/zach/install4j/bin/install4jc --release=9.1-SNAPSHOT --destination="/home/zach/projects/java/ehdtrunk/target/install4j" -D m2_home=${settings.localRepository} /home/zach/projects/java/ehdtrunk/newinstaller/ehd.install4j
  </code></pre>
  
  <p>Is this the fault of the plugin? If so, what needs to change to allow the substitution to happen?</p>