added support for V4L2_PIX_FMT_YUV420 and made it default

tested with Logitech QuickCam only!
imported ccvt lib from player v4l driver
renamed uvc_camera uvc_camera_yuv
completed rename to uvc_camera_yuv
added camera info to manifest.xml
add .gitignore
Merge remote-tracking branch 'upstream/master'

Conflicts:
	uvc_camera_yuv/CMakeLists.txt