entry: Make DnD coordinate calculation compensate for entry icons
entry: Make DnD coordinate calculation compensate for entry icons

This made DnD have effect farther on the left when dragging text over
any entry with icons in it.

https://bugzilla.gnome.org/show_bug.cgi?id=725866

ahodesuka/gtk,ahodesuka/gtk,jadahl/gtk,jessevdk/gtk,jadahl/gtk,jadahl/gtk,chergert/gtk,jessevdk/gtk,msteinert/gtk,grubersjoe/adwaita,jigpu/gtk,jigpu/gtk,jadahl/gtk,grubersjoe/adwaita,Adamovskiy/gtk,Lyude/gtk-,davidgumberg/gtk,alexlarsson/gtk,jessevdk/gtk,jigpu/gtk,msteinert/gtk,alexlarsson/gtk,jigpu/gtk,Adamovskiy/gtk,Lyude/gtk-,jigpu/gtk,grubersjoe/adwaita,jigpu/gtk,chergert/gtk,alexlarsson/gtk,Lyude/gtk-,Sidnioulz/SandboxGtk,jessevdk/gtk,chergert/gtk,Sidnioulz/SandboxGtk,ahodesuka/gtk,ahodesuka/gtk,Adamovskiy/gtk,alexlarsson/gtk,Lyude/gtk-,jessevdk/gtk,msteinert/gtk,ahodesuka/gtk,grubersjoe/adwaita,Adamovskiy/gtk,jessevdk/gtk,alexlarsson/gtk,chergert/gtk,Lyude/gtk-,davidgumberg/gtk,Sidnioulz/SandboxGtk,Sidnioulz/SandboxGtk,Sidnioulz/SandboxGtk,ahodesuka/gtk,chergert/gtk,jigpu/gtk,chergert/gtk,jadahl/gtk,Adamovskiy/gtk,jadahl/gtk,msteinert/gtk,Adamovskiy/gtk,alexlarsson/gtk,Lyude/gtk-,alexlarsson/gtk,Adamovskiy/gtk,Lyude/gtk-,Lyude/gtk-,chergert/gtk,davidgumberg/gtk,grubersjoe/adwaita,msteinert/gtk,jadahl/gtk,davidgumberg/gtk,jigpu/gtk,Sidnioulz/SandboxGtk,jadahl/gtk,grubersjoe/adwaita,ahodesuka/gtk,grubersjoe/adwaita,davidgumberg/gtk,jessevdk/gtk,Adamovskiy/gtk,grubersjoe/adwaita,davidgumberg/gtk,ahodesuka/gtk,alexlarsson/gtk,chergert/gtk,davidgumberg/gtk,msteinert/gtk,davidgumberg/gtk