qt5webkit-examples: new package

[Thomas: remove QT5WEBKIT_EXAMPLES_INSTALL_STAGING = YES.]

Signed-off-by: Massimo Callegari <massimocallegari@yahoo.it>
Signed-off-by: Fatih Aşıcı <fatih.asici@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>