[#957] make FunctionalTest work with asynchronous controllers

[#957] removed unused import after changing the completion detection

[#957] throw TimeoutException on long running tests, like before probably

[#957] me, being pedantic about placing import statements

[#957] improved test runner to not deadlock on functional tests of asynchronous controllers

[#957] fixed indentation

[#957] issue #116 has been fixed, we can clean this up in the process

[#957] removed dependency from model validator to current HTTP request

[#957] adapted test; this should not throw an exception within the test, but report an HTTP error

[#957] seems to improve on spurious test failures by using selenium in a more robust way

[#957] loosen constraints in timing dependent code to make test more reliable