cleanup + add LinuxCamera controls

- [Blackbox] add Enable/Disable functions - [Console] exit thread when flight is run as a daemon - [GPIO] export Read/Write functions to LUA - [Stabilizer] comment-out altitude-hold for now

Update prebuilt image

bugfixes + use pigpio in controller_rc + quieter telemetry

Update README.md

* config and lua cleanup with new Sensor::infos() member. * Better altitude estimation using BMP280. * new GET_CAMERAS_INFOS Controller command. * Add missing files to image builder. * Update openh264 includes.

Add pre-built image to README.md

image generator : fix startup script

add basic config in image builder

Merge branch 'master' of ssh://github.com/dridri/bcflight