title: eclipse xtext plugin versions compatibility with eclipse IDE
body: <p>I made a plugin in eclipse juno using xtext, I package my plugin using the following tutorial: <a href="http://www.vogella.com/articles/EclipsePlugIn/article.html#p2deployplugin" rel="nofollow">http://www.vogella.com/articles/EclipsePlugIn/article.html#p2deployplugin</a> ... sec 6.Create update site for your plug-in and I install it in the same version of eclipse IDE and the installation was successful. I need install it in others versions of eclipse's (Helios, Galileo, etc.) but when i try to install in Helios appear the following message: </p>
  
  <pre><code>Cannot complete the install because one or more required items could not be found.
    Software being installed: MView Source 1.0.0.201308011127 (MView.feature.group 1.0.0.201308011127)
    Missing requirement: MView Source 1.0.0.201308011127 (MView.feature.group 1.0.0.201308011127) requires 'org.eclipse.xtext 2.0.0' but it could not be found.
  </code></pre>
  
  <p>I searched for org.eclipse.xtext 2.0.0 jar to add to the dependencies but i dont found it. 
  I don't know if this will work but I wanted to ask if there are some way to make my plugin compatible with various versions of eclipse IDE and how. compatible with backward versions and forward versions. I would appreciate any information about it. Sorry for my English Thank you very much. =)</p>