OpenPTV Documentation 0.0.04 Clean Branch - from Jimmy 

Hi, 

I copied Jimmy files from his /docs into a clean copy of origin/master/docs and checked that it compiles. see the product on http://alexlib.github.io/docs

I confirm that we can pull this request. Please, review. Note that this pull request follows and replaces the https://github.com/OpenPTV/openptv-python/pull/15

Thanks to Jimmy and Yulia for the work.