update to latest libav code
remove format dump
move out av code
integrate av to context
move out the device finder
clear semantics
message if can't open video
mfc: force to V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE
use v4l2_mfc_g_fmt
mfc: simplify querybuf
include headers guards
simplify map_planes
tests
simplify v4l2_mfc_qbuf
we're copying ourselves\!
comment and code style
Revert "use v4l2_mfc_g_fmt"

This reverts commit f7a5c77745b46e87adb42cca52b49157e37dacce.

Conflicts:
	main.c
simplify v4l2_mfc_streamon
simplify v4l2_mfc_reqbufs
assert the number of planes