Readded Integration tests

[martinheidegger]

Based on #529 this PR readds the integration tests and fixes a few bugs.

Highlighting the changes:

1. It reintroduces command line options to specify where the data should be stored: 51c3b24
2. It reintroduces the formerly missing dat document title: 3b5336f
3. It reintroduces the former lib/monkeyPatch.js to make sure that the sharing of folders can be tested: 1fb670e
4. It stops opening the developer tools (as this prevents the integration tests, and it shouldn't land in the deployment anyways): ff25ba8#diff-168726dbe96b3ce427e7fedce31bb0bcL37
5. It introduces consistent css-classnames for buttons as it was hard to figure out in the tests what is happening: 6273b03
6. Kept only integration tests in tests/index.js, the other tests are covered by unit tests now.

[martinheidegger]

Let me merged this PR into add/download to, and continue the add/download branch