title: MEF Loading and Unloading specific Plugin?
body: <p>i'm new in the plugin world and force to unterstood mef. 
  Currently i know how i can load plugins from a specific folder.
  Now i have some questions:</p>
  
  <ul>
  <li>Can i load plugins from a folder which are specify in a configuarations file (Serialization) ?</li>
  <li>How i can unload plugins ?</li>
  <li>How can i load plugins with a specific version between min&amp;max version?</li>
  <li>How i can wrap the catalog &amp; compose e.g. as something like "MEF Manager"</li>
  </ul>
  
  <p>optionaly:</p>
  
  <ul>
  <li>How i can display forms from plugin?</li>
  </ul>
  
  <p>thanks for help</p>