entry: Improve positioning of touch selection magnifier
entry: Improve positioning of touch selection magnifier

Always show completely above or below entry to avoid covering
content, and limit horizontal position so it doesn't overflow
to the right.

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