engine: Cleanup and normalize log messages.
engine: Cleanup and normalize more log messages.
core: Removing test_core and replacing with tc_core.rb.
core - .first() and .last(): Transformations treat non-list inputs as single element lists, returning the input field as the output field.
core first() / last(): Adding Clipp tests for first() and last() transformations.
modules: Cleanup and normalize log messages.