Fail faster.
Suppress ugly exception log on expected exceptions

When XCTestCase tries recording the thrown exception, check whether or
not it’s a “stop” exception.  If so, suppress the logging.  Resolves
issue #401.
Log failures in beforeAll/afterAll correctly.

Failures weren’t getting logged since they weren’t part of a test run.
This logs the errors and signals to the test suite to skip the rest of
the tests.
Added Swift example; updated README
Added shared scheme.
Merge pull request #488 from kif-framework/puls/update-readme

Added Swift example; updated README