v1.4.0

• virt-manager: spice GL console support (Marc-André Lureau, Cole Robinson)
• Bump gtk and pygobject deps to 3.14
• virt-manager: add checkbox to forget keyring password (Pavel Hrdina)
• cli: add --graphics gl= (Marc-André Lureau)
• cli: add --video accel3d= (Marc-André Lureau)
• cli: add --graphics listen=none (Marc-André Lureau)
• cli: add --transient flag (Richard W.M. Jones)
• cli: --features gic= support, and set a default for it (Pavel Hrdina)
• cli: Expose --video heads, ram, vram, vgamem
• cli: add --graphics listen=socket
• cli: add device address.type/address.bus/...
• cli: add --disk seclabelX.model (and .label, .relabel)
• cli: add -cpu cellX.id (and .cpus, and .memory)
• cli: add --network rom_bar= and rom_file=
• cli: add --disk backing_format=
• Many bug fixes and improvements