convert GalleryBrowserTravel to scoped enum

and drop unused GALLERYBROWSERTRAVEL_CURRENT value

Change-Id: Id91824cbe024d4b5109ee0755b518164837bc6a6
Reviewed-on: https://gerrit.libreoffice.org/33965
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

compilerplugins/clang/unusedenumconstants.py

@@ -100,6 +100,9 @@ for d in definitionSet:
          "framework/inc/helper/mischelper.hxx",
          "include/svtools/htmltokn.h",
          "include/sfx2/shell.hxx",
+         "sw/inc/iodetect.hxx",
+         "sw/inc/fmtfordr.hxx",
+         "sw/inc/flddat.hxx",
         # Windows or OSX only
          "include/canvas/rendering/icolorbuffer.hxx",
          "include/vcl/commandevent.hxx",