fixed libvlc loading, search for vlc in environment PATH on windows if not found in registry (cherry picked from commit 9bd43bbbbfc9daf1eb50cfa9c398a3d2b84b900e)
fixed libvlc loading, search for vlc in environment PATH on windows if not found in registry
(cherry picked from commit 9bd43bbbbfc9daf1eb50cfa9c398a3d2b84b900e)

Signed-off-by: Jean-Baptiste Kempf <7b85a41a628204b76aba4326273a3ccc74bd009a@videolan.org>

BinChengfei/phonon-vlc,KDE/phonon-vlc,KDE/phonon-vlc,BinChengfei/phonon-vlc,KDE/phonon-vlc,panzi/phonon-vlc,panzi/phonon-vlc,BinChengfei/phonon-vlc