Pt. 1 of fix for #889723, scales nodes on redraw
Pt. 1 of fix for #889723, scales nodes on redraw

Now the blue nodes for selection resize are scaled properly when a
selection is made (depending on zoom level), but still don't scale
up and down when zoom is changed.

PintaProject/Pinta,Fenex/Pinta,jakeclawson/Pinta,Mailaender/Pinta,PintaProject/Pinta,Fenex/Pinta,jakeclawson/Pinta,PintaProject/Pinta,Mailaender/Pinta