Quick Crop buttons for .5 seconds

[dariusz-wozniak]

Hi! Thank you a lot for the open-source app!

I'd like to ask - maybe it would be more convenient to add cropping to 1.5 seconds (as a button)? I'm using the 1.5 by default in almost all scenarios.

[agsalguero]

I`ve just created a pull request on the video_trimmer subproject that adds 1.5 button to the app: KyleKun/video_trimmer#1. I hope it helps.