nihav-movrender: alpha release

I’ve decided to make a code drop release of nihav-movrender just for the completeness sake. If you look at nihav.org you should be able to find its git bundle among the rest. One of the hardest parts was to create some documentation for it, so I’ve put something into README.md, hopefully that will be enough for all zero people who want to try it. Essentially if you provide it with the name of input MOV file and output directory it will try to decode the former and create some files in the latter (and if you omit output directory, it will put them into the current directory and you’ll have yourself me to blame for that). For tweaking that behaviour you need to refer either to nihav-movrender --help or to the aforementioned documentation. Even in the current imperfect form it solves the tasks I wanted it to solve: extract (and convert to more convenient format) more exotic QuickTime tracks, and merge otherwise less accessible tracks (panoramas or multiple description tracks). The only…