Implementation of beforeAll/afterAll

This pull request adds the functions `beforeAll` and `afterAll` to be used inside any test suite. With these functions we can better create a test window for a complete test suite and close it at the end. Hopefully, if jasmine finally implements them, we won't need to rewrite anything besides removing the additional code added on this PR.

I then updated the test suites that used a single window for all the tests to use this new functions.