In the motion compression phase the coalesced events will be saved
as a GdkTimeCoord on the motion event that shall be delivered.
For simplicity (and because history doesn't make much sense otherwise)
event history is only recorded while there are buttons pressed, this
also tidily ensures that those coalesced events would have the same
target widget on the gtk side than the delivered one, because of
implicit grabs.
Two warts remain. gdk_event_copy() should be unnecessary as
events should be considered static after delivery, so g_object_ref()
should be just as good. There's a few exceptional cases that the event
is copied and then modifier for later processing, those cases should be
reconsidered individually.
And gdk_event_free() could be likewise turned into g_object_unref(),
many callers remain though.
Now all events structs are private, it doesn't make as much sense
having GdkEventPrivate wrapping allocating events. This is a first
step towards removing it.
It won't stand true anymore that the GdkEventType argument is the
first field of the GdkEvent* structs. All callers have been updated
to use event->any.type instead.
We are not emitting these events anymore, so lets remove them
from the api. The GdkSettingAction enum is moved to xsettings-client.c
where its only use remains.
Those should be interpreted by widget-local gestures, not guessed at a
high level with no notions of the specific context. Users will want
GtkGestureMultiPress to replace these events.
