Expose package type to eclipse

[gossi]

I don't know how to exactly call that. The package type should be made accessible from a plugin.xml. So other plugins can register menu items and filter it based on the composer type or decorate folders based on it. Similar to what pdt makes available
org.pdtextensions.parentProjectNature:

<menuContribution
            allPopups="false"
            locationURI="menu:sourceMenuId?before=sourceBegin">
         <command
               commandId="com.dubture.composer.ui.command.injectAutoload"
               label="Inject Composer Autoload-Statement"
               style="push">
            <visibleWhen checkEnabled="false">
               <with
                     variable="selection">
                  <iterate
                        ifEmpty="false"
                        operator="and">
                          <test
                                forcePluginActivation="true"
                                property="org.pdtextensions.parentProjectNature"
                                value="com.dubture.composer.core.composerNature">
                          </test>
                  </iterate>
               </with>

            </visibleWhen>
         </command>
      </menuContribution>