Add a setting for the view to be shown at start

[EvysGarden]

Problem

My camera is a bit slow and i have to wait for a few seconds every time i start the app.

Solution

As the title says, i'd like this app to have the option to select the start view.
I don't always want to scan something, so it would be more efficient for me to start the app on the history or the create fragment.

Pull request

I have implemented this functionality on my branch and will submit it shortly.

(I don't have much experience with commits and pull requests so please be nice and feel free to correct me on my errors ^^ )

[EvysGarden]

See #132