GtkEntry: Make progress pulsing smooth
GtkEntry: Make progress pulsing smooth

This changes the calculation of activity mode progress in the
same way as was done in GtkProgressBar a while ago, and make it
smooth, using a tick callback.

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