Use qt5 booster instead of generic one.

[boosting] Use qt5 booster instead of generic one.

Signed-off-by: Marko Saukko <marko.saukko@jolla.com>
Drop qt4 packaging.

[packaging] Drop qt4 packaging.

Signed-off-by: Marko Saukko <marko.saukko@jolla.com>