title: how to unlock edition of pom.xml in tab "Effective POM" on eclipse mars 4.5.0
body: <p>I want to modify the content of pom.xml, but i cant edit it in "Effective POM" tab , eclipse mars 4.5.0 </p>
  
  <blockquote>
    <p>I try to edit it as common files but no change on keydown</p>
  </blockquote>