bgo#315462 - Make GtkLabel deal with too-small height allocations gracefully
bgo#315462 - Make GtkLabel deal with too-small height allocations gracefully

Previously we would always align the top of the text with the label's allocation-plus-padding.
However, this makes a single-line label inside a GtkButton look badly clipped when the button
has a smaller allocation than its requisition.  So, for single-line labels we respect the
alignment even if it doesn't fit within the label's allocation.  But for multi-line labels, we
give preference to showing the first line, to give the user some context.

Signed-off-by: Federico Mena Quintero <4999915a961edfd7686112c2935288e1266eae14@novell.com>

simokivimaki/gtk,chipx86/gtk,grubersjoe/adwaita,jigpu/gtk,chipx86/gtk,Distrotech/gtk,Lyude/gtk-,nacho/gtk-,Adamovskiy/gtk,bratsche/gtk-,chergert/gtk,Distrotech/gtk,simokivimaki/gtk,Adamovskiy/gtk,ebassi/gtk,jigpu/gtk,alexlarsson/gtk,bratsche/gtk-,Unity-Technologies/gtk,nacho/gtk-,jadahl/gtk,Distrotech/gtk2,johne53/MB3Gtk-2,jadahl/gtk,Adamovskiy/gtk,jadahl/gtk,davidt/gtk,Distrotech/gtk2,jadahl/gtk,alexlarsson/gtk,chergert/gtk,davidt/gtk,nacho/gtk-,alexlarsson/gtk,msteinert/gtk,jessevdk/gtk,ahodesuka/gtk,jadahl/gtk,msteinert/gtk,Sidnioulz/SandboxGtk,jigpu/gtk,grubersjoe/adwaita,ahodesuka/gtk,msteinert/gtk,jadahl/gtk,chipx86/gtk,jessevdk/gtk,chergert/gtk,davidgumberg/gtk,bratsche/gtk-,jessevdk/gtk,davidt/gtk,jadahl/gtk,davidt/gtk,chipx86/gtk,grubersjoe/adwaita,bratsche/gtk-,ahodesuka/gtk,Unity-Technologies/gtk,Distrotech/gtk,Sidnioulz/SandboxGtk,Lyude/gtk-,Adamovskiy/gtk,Lyude/gtk-,jigpu/gtk,johne53/MB3Gtk-2,davidt/gtk,jessevdk/gtk,ahodesuka/gtk,ebassi/gtk,Adamovskiy/gtk,Lyude/gtk-,alexlarsson/gtk,zsx/gtk,alexlarsson/gtk,Distrotech/gtk2,ahodesuka/gtk,alexlarsson/gtk,grubersjoe/adwaita,davidgumberg/gtk,Sidnioulz/SandboxGtk,jigpu/gtk,johne53/MB3Gtk-2,johne53/MB3Gtk-2,bratsche/gtk-,ebassi/gtk,davidgumberg/gtk,nacho/gtk-,Unity-Technologies/gtk,zsx/gtk,Lyude/gtk-,jigpu/gtk,Adamovskiy/gtk,grubersjoe/adwaita,Distrotech/gtk,davidt/gtk,jessevdk/gtk,zsx/gtk,johne53/MB3Gtk-2,simokivimaki/gtk,ebassi/gtk,msteinert/gtk,bratsche/gtk-,jadahl/gtk,simokivimaki/gtk,chipx86/gtk,Sidnioulz/SandboxGtk,Distrotech/gtk2,ebassi/gtk,davidgumberg/gtk,Sidnioulz/SandboxGtk,davidgumberg/gtk,simokivimaki/gtk,Distrotech/gtk,chergert/gtk,Adamovskiy/gtk,chergert/gtk,jessevdk/gtk,Unity-Technologies/gtk,zsx/gtk,davidgumberg/gtk,grubersjoe/adwaita,nacho/gtk-,grubersjoe/adwaita,grubersjoe/adwaita,Lyude/gtk-,ahodesuka/gtk,chergert/gtk,Lyude/gtk-,ahodesuka/gtk,jigpu/gtk,ebassi/gtk,alexlarsson/gtk,jigpu/gtk,ahodesuka/gtk,Unity-Technologies/gtk,Adamovskiy/gtk,davidgumberg/gtk,msteinert/gtk,Sidnioulz/SandboxGtk,alexlarsson/gtk,Distrotech/gtk2,chergert/gtk,davidgumberg/gtk,Distrotech/gtk2,simokivimaki/gtk,zsx/gtk,Lyude/gtk-,jessevdk/gtk,msteinert/gtk,chergert/gtk