[WIP] Android camera app

[niccokunzmann]

This is a try to use an android app instead of an html app.
The reason:

• HTML camera access works on modern browsers
• HTML camera access is limited to a video which has lower quality than we desire. https://stackoverflow.com/a/26501469

Roadmap:

• (app) Write an app
• (app)Get a picture from the camera
• (app) use back camera
• (app) use maximum resolution
• (app) compatible with Android 2.3
• (app) input the openbookscanner ip
• (app) ask the bookscanner if the app should take a picture
  python -m openbookscanner.states.scanner_app_test
• (bookscanner) add a finder for camera scanners
• (bookscanner) add a camera scanner
• (app) send the picture to the openbookscanner
• (bookscanner) receive the pictures from the camera
• (bookscanner) pass the pictures as scan

later:

• auto discover the openbookscanner https://developer.android.com/training/connect-devices-wirelessly/nsd
• increase picture quality by maximizing contrast