`SLTest` now exposes the currently-running test case.

For logging purposes.
`SLTestController` tracks the currently-running test.

For logging purposes.
Subliminal's uncaught exception handler logs the current test (case).
Correct the identification of test case names in `subliminal_uialog_to_unit`.

Test cases are always instance methods, so their names always begin with the '_'
character.
Remove a misleading `if` statement in `subliminal_uialog_to_unit`.

Matching the test suite is not optional.
Do not unnecessarily capture the test suite when processing test cases in
`subliminal_uialog_to_unit`.

This information is unused here.
`subliminal_uialog_to_unit` logs uncaught exceptions as test case errors. (fixes #50)
Merge pull request #51 from inkling/jeff/log_uncaught_exception_context

Log uncaught exceptions as test case errors.