Renamed ``smoke/test_smoke.py`` and refactoring.

Renamed ``smoke/test_smoke.py`` to ``smoke.test_cli_smoke.py`` to
reflect that all tests contained within this suite use the CLI layer.
Also performed some refactoring and updated docstrings.
Adding initial ``smoke`` tests for API.

Added initial ``smoke`` tests using the API layer. Further iterations
will be necessary to cover all areas as described in the docstrings, but
all existing tests are currently passing.
Handled feedback from Jeremy Audet.
Merge pull request #1099 from omaciel/api-smoke

Api smoke