yi-hack-Allwinner 0.2.8

Fix RTSP server segfault
Update mqttv4 to the last release
Add github link to the status page
Improve camera settings web page
Improve code for SD detection
Add delay before snapshot
Add unbrick folder
Improve validation of web input
Fix path for PTZ commands
Add pcmvol to change speaker volume
Improve h264grabber with fifo and "both" option
Add alternative rtsp server
Update live555 to the last version
Add auto detection of framebuffer size