Search tool 7

The rebased version of the search-tool-6 branch.

The VS related code was moved from services to the AppController
There is only one issue about it, the travis build fails, because in the ```login()``` function the following line fails:
```
driver.find_element_by_link_text("Sign in").click()
```

But I haven't changed anything around user authentication, so if somebody can help me interpret this, I'd greatly apprechiate  it. (Build log: https://travis-ci.org/hypothesis/h/builds/10057354 )