Improved Kramdown::ElementRt API
Added mixins for enhanced kramdown tree post-processing after folio import.
Updated Kramdown::Element.is_of_same_type? to ignore 'id' attr.
Added specs for kramdown tree post processing mixins
Fixed two bugs in ConvertAbbreviationsToLowerCase
Added missing require
Added comment to ConvertAbbreviationToLowerCase
folio import: remove underscores from paragraph numbers
folio import: fixed bug where regex back reference wasn't escaped properly and resulted in unicode char \1