add several parse methods to gst.Message
add several parse methods to gst.Message

LittleBuster/gotk3,yamnikov-oleg/gotk3,pekim/gotk3,yamnikov-oleg/gotk3,andre-hub/gotk3,yamnikov-oleg/gotk3,andre-hub/gotk3,gotk3/gotk3,LittleBuster/gotk3,andre-hub/gotk3,pekim/gotk3,pekim/gotk3,gotk3/gotk3