Added support to limit module execution to a specific range of repository versions.

e.g. the PHP SDK module has the following:
   module.repo.version.min=2.0
   module.repo.version.max=2.1
This limits it to being installed on 2.0 or 2.1 versions of Alfresco.
Roy can change this, if required.


git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@5532 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261

source/java/org/alfresco/service/descriptor/Descriptor.java

@@ -24,6 +24,8 @@
  */
 package org.alfresco.service.descriptor;
 
+import org.alfresco.util.VersionNumber;
+
 
 /**
  * Provides meta-data for the Alfresco stack.
@@ -67,6 +69,11 @@ public interface Descriptor
      */
     public String getVersionBuild();
     
+    /**
+     * @return Returns the object representing the major-minor-revision numbers
+     */
+    public VersionNumber getVersionNumber();
+    
     /**
      * Gets the full version number
      *