Feature request: crop video

[jessesmith]

I would like to see an effect added to OpenShot which would allow the user to crop the edges of a given frame. Let's say, for example, I have a video clip and I notice there is something in the far right I want to remove. I would like to be able to select a Crop effect and tell it to remove N number of pixels from the right side of the frame.

As a reference, the PiTiVi editor recently gained this feature in their git repository. (http://www.pitivi.org/)