Unit tests for xctool not crashing on assertion failures

* Renamed test bundle directory by dropping the 'otest-query' prefix and updated references
* Added assertion test bundles
* Exposed -[OCUnitIOSLogicTestRunner otestTaskWithTestBundle]
* Added OTestShimTests to test otest and xctest behavior
Fixed crashing on assertion failures on XCTest bundles.

Fixes issue #198.