[qt5-qtbase/f19] (7 commits) ...-gui: don't require gtk2 (__requires_exclude_from platformthemes) (#1154884)

[Kevin Kofler]

Summary of changes:

  5006fbb... split the old_xcb patch into old_xcb and old_xkbcommon (*)
  e26fd4f... F20: require libxkbcommon >= 0.4.1, only patch for the old  (*)
  c6628db... use linux-g++ platform unconditionally (*)
  ab7b18b... QFileDialog: implement getOpenFileUrl and friends for real (*)
  fd495c7... Fix build (*)
  1d141c1... Fix build one more time (*)
  04d5416... -gui: don't require gtk2 (__requires_exclude_from platformt (*)

(*) This commit already existed in another branch; no separate mail sent