title: Maven: mavent--ant-run does not support attribute
body: <p>Currently I'm working on a maven build script and my next issue is to copy source files into a target folder. I found this <a href="https://stackoverflow.com/questions/4257858/maven-copy-files-without-subdirectory-structure">thread</a> and it works fine unless I don't use the 'flattern' attribute. I know that the computer makes all things right, but I wonder why the build will fail.</p>
  
  <p>Here my code using the maven antrun plugin:</p>
  
  <pre><code>&lt;build&gt;
   &lt;plugins&gt;
    &lt;plugin&gt;
      &lt;artifactId&gt;maven-antrun-plugin&lt;/artifactId&gt;
      &lt;version&gt;1.7&lt;/version&gt;
      &lt;executions&gt;
       &lt;execution&gt;
        &lt;phase&gt;process-resources&lt;/phase&gt;
        &lt;configuration&gt;
         &lt;target&gt;
          &lt;copy todir="${project.basedir}/target"  flattern="true" overwrite="true"&gt;
           &lt;fileset dir="${project.basedir}/src/main"/&gt;
          &lt;/copy&gt;
         &lt;/target&gt;
        &lt;/configuration&gt;
        &lt;goals&gt;
         &lt;goal&gt;run&lt;/goal&gt;
        &lt;/goals&gt;
       &lt;/execution&gt;
      &lt;/executions&gt;
    &lt;/plugin&gt;
   &lt;/plugins&gt;
  &lt;/build&gt;
  </code></pre>
  
  <p>The error message I get is</p>
  
  <pre><code>[ERROR] Failed to execute goal org.apache.maven.plugins:maven-antrun-plugin:1.7:run (default) on project setup_core: An Ant BuildException has occured: copy doesn't support the "flattern" attribute
  [ERROR] around Ant part ...&lt;copy todir="C:\Projekte\CQ5_Migration\setup\core_upload/target" overwrite="true" flattern="true"&gt;... @ 4:101 in C:\Projekte\CQ5_Migration\setup\core_upload\target\antrun\build-main.xml: The &lt;copy&gt; type doesn't support the "flattern" attribute.
  [ERROR] -&gt; [Help 1]
  </code></pre>
  
  <p>Have I overseen somthing and if so what is/are the missing fact(s)?</p>
  
  <p>Thanks again for your help :-)</p>