Correctly capitalise GNOME in the Manual and man page (#739805)

The GNOME Logo & Trademarks page
(http://www.gnome.org/logo-and-trademarks/) says:
    * All the letters in "GNOME" should be capitalized.

Also correctly capitalise the program name as GNOME Partition Editor in
the Manual, and gparted.doap file (used in web git browser).

Bug 739805 - GNOME is incorrectly capitalised on the website and else
             where