Revised file processing screens on the backside of miniLock

Here is an implementation of the human interface design mentioned in issue #42.

And 3 videos that show it off:

Alice encrypts passport to Bob
https://vimeo.com/101773171

Save a secret song for my parents
https://vimeo.com/101773412

Crazy Town
https://vimeo.com/101773420
Sure, we can push this in as is for now, but this needs to change. You don't have to fix this yourself, by the way. I can do it; I'm just saying that in general this practice shouldn't be adopted.