Branch gnome 3.12
baobab: add 3.12.1 version and cleanup expr
gnome-icon-theme: add 3.12.0 version
evince: add 3.12.1 version
eog: add 3.12.2 version
libgnome-keyring: add 3.12.0 version
totem: add 3.12.1 version
yelp: add 3.12 version
gnome-session: add 3.12.1 version
gnome-shell: add 3.12.2 version
gnome-common: add 3.12.0 version
gnome-desktop: add 3.12.2 version
gnome-screenshot: add 3.12.0 version
gnome-system-monitor: add 3.12.2 version and cleanup expr
gnome-calculator: add 3.12.1 version and cleanup expr
gnome-icon-theme-symbolic: add 3.12.0 version
gnome-backgrounds: add 3.12.2 version
gnome-contacts: add 3.12.0 version and cleanup expr
gnome-user-docs: add 3.12.1 version
gnome-terminal: add 3.12.2 version