Added a method to AVMService and its dependent services to get an InputStream

directly from a node descriptor.  It's a minor optimization for a few use
scenarios.  It's also convenient for accessing content of historical file
versions directly.  
Another CLT, to list the versions of a store.


git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@4496 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261

source/java/org/alfresco/service/cmr/avm/AVMService.java

@@ -53,6 +53,14 @@ public interface AVMService
      */
     public InputStream getFileInputStream(int version, String path);
     
+    /**
+     * Get an InputStream from a descriptor.
+     * @param desc The descriptor.
+     * @return An InputStream.
+     * @throws AVMNotFoundException
+     */
+    public InputStream getFileInputStream(AVMNodeDescriptor desc);
+    
     /**
      * Get an output stream to a file node.  The file must already exist.
      * @param path The simple absolute path to the file node.