o Use MASTER_SITE_GNOME

o Fix remaining packages to install documentation into
  share/doc instead of share/gtk-doc (usually,
		  CONFIGURE_ARGS+=        --with-html-dir=${PREFIX}/share/doc/html
  does the trick; additionally, one might set
		  CONFIGURE_ARGS+=        --enable-gtk-doc=no
  to avoid a gtk-doc dependency if html documentation is
  shipped with the package). Please fill in GNOME bug
  reports if any of the packages do not honor these
  configuration options and/or do not ship with pregenerated
  html documents.