introduce get_tree request (tree branch only)
introduce get_tree request (tree branch only)

i3/i3,stapelberg/i3,Airblader/i3-original,Airblader/i3,cornerman/i3,Airblader/i3,stapelberg/i3,cornerman/i3,stapelberg/i3,stapelberg/i3,cornerman/i3,i3/i3,Airblader/i3-original,Airblader/i3,i3/i3,Airblader/i3,Airblader/i3-original,cornerman/i3,i3/i3,Airblader/i3-original,Airblader/i3-original