[$] Access to complex video devices with libcamera

Laurent Pinchart began his OpenSource Summit Japan 2019 talk with a statement that, once upon a time, camera devices were simple pipelines thatproduced a sequence of video frames. Applications could control cameras usingthe Video4Linux (V4L) API by way of a single device node; there were "lots ofknobs", but the overall task was straightforward. That situation haschanged over the years, and application developers need more help; that iswhere the libcamera project comes in.