libvlc: intf-show and intf-popmenu must be created before interfaces are launched (via use of --extraintf)
libvlc: intf-show and intf-popmenu must be created before interfaces are launched (via use of --extraintf)

This fixes 'vlc -I rc --extraintf skins' that fails to add a callback to these
variables because they are not yet created
(pointed out by assert failed in debug mode when calling var_DelCallback)

shyamalschandra/vlc,jomanmuk/vlc-2.2,vlc-mirror/vlc-2.1,vlc-mirror/vlc-2.1,krichter722/vlc,jomanmuk/vlc-2.1,jomanmuk/vlc-2.2,jomanmuk/vlc-2.2,vlc-mirror/vlc,krichter722/vlc,shyamalschandra/vlc,jomanmuk/vlc-2.2,jomanmuk/vlc-2.2,vlc-mirror/vlc-2.1,vlc-mirror/vlc-2.1,krichter722/vlc,shyamalschandra/vlc,krichter722/vlc,jomanmuk/vlc-2.2,shyamalschandra/vlc,jomanmuk/vlc-2.1,xkfz007/vlc,krichter722/vlc,vlc-mirror/vlc-2.1,xkfz007/vlc,xkfz007/vlc,vlc-mirror/vlc,vlc-mirror/vlc,vlc-mirror/vlc,xkfz007/vlc,vlc-mirror/vlc-2.1,jomanmuk/vlc-2.1,vlc-mirror/vlc,krichter722/vlc,krichter722/vlc,xkfz007/vlc,shyamalschandra/vlc,jomanmuk/vlc-2.1,shyamalschandra/vlc,shyamalschandra/vlc,xkfz007/vlc,jomanmuk/vlc-2.1,vlc-mirror/vlc-2.1,jomanmuk/vlc-2.1,vlc-mirror/vlc,xkfz007/vlc,vlc-mirror/vlc,jomanmuk/vlc-2.2,jomanmuk/vlc-2.1