This is a merge+manual adaptations of numerous commits on Qt4

(cherry picked from commit 99b7cf3c3f0d554bf3175082a32722e78bb0f4e8)
(cherry picked from commit 7e26f748884c337eeafdd55c403c5ebce7e90f80)
(cherry picked from commit 8abd25d4f52c23e6c19f40740e3aaafc385c0e73)
(cherry picked from commit a736053c00778ca35f8653713517558e1e710aea)
(cherry picked from commit 312d9c3fc4dee049bf25288d7a3f519003c817b4)
(cherry picked from commit 6fac93217a965a843046e4c0c814cc161a4e0cc8)
(cherry picked from commit df261c30a4ec89baee1c7b3a1152b846d0bc80a7)
(cherry picked from commit a70095543572745dca9b9ef1c776ed751e76d936)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>