Log Message:
PC6001VX: update to 2.33.0.

pkgsrc changes:
 * png files for README.html are no longer installed (embedded into the htlm)

Upstream changelog:

2.33.0 2018/04/28

 * Support FFMpeg4.0.
 * Changed Video Capture bitrate to YouTube recommended value.
   (video:4Mbps,audio:128Kbps)
 * Embedded images to README.html. So doc folder is no longer distributed
   with Windows binary.