Changed layout to /layout {arrange,mix,edit}

Sending of:
/layout {arrange,mix,edit}

/arranger/cueMarkerVisibility
/arranger/playbackFollow
/arranger/trackRowHeight

/mixer/clipLauncherSectionVisibility
/mixer/crossFadeSectionVisibility
/mixer/fx
/mixer/ioSectionVisibility
/mixer/meterSectionVisibility