Release 2.1

A lot of work has been done on this project since its start in 2018 and multiple features have been added during these 3 years.
The time has come to fix it as a release. I am deciding the future if this project, cause some really required features (like image sequence transcoding) are missing. I am not sure I want to implement this mess in windows batch, and thinking of a new python based utility, more sleek and more powerful. Still this project serves me very well in my everyday work, hope so does it for you.