Updated ImportWhitespaceSanitizer to recurse if it makes any changes to handle multiple adjacent elements (at beginning or end of paragraph) that require whitespace sanitization.
Updated Folio parser to do another pass of whitespace sanitization to handle some edge cases in Spanish Folio import.
Added KeContext#replace_current_text_container_with method to be able to replace :br tags with :p tags when importing Folio.
Improved reporting when comparing kramdown elements and trees
Updated reporting for soft-hyphen invalid character validation to include some context.