GDSG Updates

["Eugene O'Connor" <eugene oconnor sun com>]

I've made the following updates to the XML for the GDSG:

   * Added new terms to the wordlist: 
     - GNOME Desktop Terms: tree. Also the following intended primarily
for system administration 
documentation: application registry, file content sniffer, MIME
information file, MIME keys file, MIME type registry, pattern mask.
     - User Actions:  press-and-hold. Also, intended primarily for
accessibility documentation: activate.
     - General Computer Terms: arrange, ask, cursor, MIME, MIME type,
prompt, screensaver, screensaver display, sort, websafe color palette.
  
   * Modified following terms: 
     - GNOME Desktop Terms: control, dialog element, drop-down list
(changed from drop-down list box), native viewport, native workspace.
     - User Actions:  delete, remove.

I also added a feedback section to style-guide.xml.

I'm hoping we can get the GDSG on the web refreshed as soon as possible
to reflect these updates.

Eugene