Log Message:
devel/difftastic: update to 0.44.0

Parsing
 - Added support for Newick and Racket.

Diffing
 - Difftastic now uses a textual diff on files that have any parse errors.
   The parse error limit defaults to 0, but it is configurable with
   DFT_PARSE_ERROR_LIMIT or --parse-error-limit.
 - Textual diffing now respects --check-only, consistent with syntactic diffing.

Display
 - Improved syntax highlighting for keywords.
 - If a file exceeds DFT_BYTE_LIMIT, difftastic now displays its size in the
   header.