(You get to love va_list type-safety)

The rationale is the same as with vlc_object_find().

Remove a bunch of ( vlc_object_t * )vlc_object_find( p_intf, VLC_OBJECT_VOUT, FIND_ANYWHERE );
and FIND_CHILD there.

Qt: Create a getVout() in MIM to remove some vlc_object_find( p_intf, VLC_OBJECT_VOUT, FIND_ANYWHERE ); calls

Just used now for buttons.

To remove, just drag n drop to the void.
To change, just drag n drop to new position.

I will need that to clarify the Toolbar editor.

And unhibit before quiting

Whether this works depends on the stream and demux behaviour. There may
be a better way to fix this.

It fixes a lot of unlocked access.
It will allows a better clock algo.