Stringified 'root' option key for consistency
Folio import: added another call to recursively_merge_adjacent_elements! to handle a new scenario in Spanish folio.
Cosmetic changes on KeContext: reordered methods alphabetically
KeContext: added `#inspect` method
Cosmetic whitespace changes
Reorganized patch specs
Added String#truncate_from_beginning, specs
Improved error message on StringComparer and Validator::SubtitleImportConsistency.

This helps when debugging text differences during subtitle_import.