Support the new tool_mobile_minimumversion setting

Test on one device of each OS. (one iOS, one Android).
You'll need blocked issues to be integrated to test that.

Some testing notes:

1. As admin on web, go to Site administration > Mobile app >Mobile authentication
2. There you'll be able to set the "Minimum app version required". Format can be:

• 4: same as 4.0.0
• 4.1: Same as 4.1.0
• 4.1.1: Same as 4.1.1

1. In the app: login on a site.
2. On the web, set a greater version that the current app: i.e 4.
3. Close and open the app again.
4. Check you're logged out, a message should be displayed indicating the version.
5. Check the Download button goes to the correct market app.
6. Click on the site to login again.
7. Check you're logged out, a message should be displayed.
8. Now navigate to settings > Syncronization.
9. Try to sync the same site. and check you're logged out again.
10. Now repeat the test with a version lower, i.e 3.5.
11. Check it does not logout.