widget: Fix display glitches with rectangular selection and wide characters

https://bugzilla.gnome.org/show_bug.cgi?id=730800
Post release version bump
build: Fix version
emulation: Keep the incoming buffer on reset

https://bugzilla.gnome.org/show_bug.cgi?id=730760
widget: Don't apply the font scale again on an already scaled font

https://bugzilla.gnome.org/show_bug.cgi?id=730858
docs: Clarify get/set_font's relation to font scale