SlotQuery use const reference to RefPtr, since it doesn't transer ownership

Conflicts:
	gstreamer/gstreamermm/pad.h
fixed query vfunc wrapper - it should not unref query object

Conflicts:
	gstreamer/gstreamermm/pad.cc
comments added

Conflicts:
	gstreamer/gstreamermm/buffer.cc
fixed create_writable in caps

Conflicts:
	gstreamer/gstreamermm/caps.cc
EventTag::parse should not take any string

Conflicts:
	gstreamer/gstreamermm/event.cc
	gstreamer/gstreamermm/event.h
taglist - Glib::Value destructo assume they are always initialized

Conflicts:
	gstreamer/gstreamermm/taglist.cc
	gstreamer/gstreamermm/taglist.h
set_accept_caps_result wrapped

Conflicts:
	gstreamer/gstreamermm/query.cc
	gstreamer/gstreamermm/query.h
basetransform: set_caps vfunc wrapped

Conflicts:
	gstreamer/gstreamermm/basetransform.cc
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