Label(): don't use misleading align argument names
Label(): don't use misleading align argument names

These arguments are forwarded to set_halign() and set_valign(), yet they
were named xalign and yalign, which is especially confusing because
Label already has completely separate xalign and yalign properties.
This could lead to users getting confused when they think they're
setting one of these pairs of properties but actually setting the other.

https://bugzilla.gnome.org/show_bug.cgi?id=774652

GNOME/gtkmm,GNOME/gtkmm,GNOME/gtkmm,GNOME/gtkmm