Stable Release v1.12.0

This is the v1.12 stable release, which brings a number of significant improvements to PX4:

The full release notes are here: https://docs.px4.io/master/en/releases/1.12.html

• Multi-EKF enabled by default
• Safety (switch) defaults to off (motors are disarmed, but servos / flaps can move)
• Safety switch is latching: Once it is disabled, it will stay disabled
• Multicopter
  • Intuitive stick feel in Position mode
  • Hover thrust independent velocity control gains
• UAVCANv0: Although the fundamental features like Firmware upgrades and parameter sync of CAN nodes have been implemented for over 5 years, we refreshed support now that finally, devices are on the market. Typical CAN GPS, airspeed and power modules are supported
• UAVCANv0 Node: PX4 supported building nodes for many years - now we support building specific targets like the CUAV GPS units
• UAVCANv1: Initial alpha of a complete end-to-end implementation
• Fixedwing/VTOL significant TECS improvements
• Magnetometer calibration faster and more robust
  • new soft iron calibration coefficients
  • automatically determine the rotation of external sensors
• Gyro dynamic notch filtering with onboard FFT
• Optimized rate control sensor pipeline (minimal inner loop end-to-end latency)
• Added support for IRC Ghost including telemetry
• new board support
  • PX4 FMUv6u
  • PX4 FMUv6x
  • CUAV X7/X7Pro
  • CUAV Nora
  • CUAV CAN GPS
  • SP Racing H7 Extreme
  • Bitcraze Crazyflie v2.1
  • ARK CAN Flow
  • ARK CAN GPS
  • Freefly CAN RTK GPS
  • mRo Ctrl Zero H7 (experimental)