• Update spec to 0.27.
• Fix warnings building with MSVC on Windows (#165, Hugh Bellamy).
• Fix CMAKE_C_VISIBILITY_PRESET for cmake versions greater than 1.8
  (e.g. 3.6.2) (#162, Hugh Bellamy). This lets us build swift-cmark
  on Windows, using clang-cl.
• Fix for non-matching entities (#161, Yuki Izumi).
• Modified print_delimiters (commented out) so it compiles again.
• make format: don't change order of includes.
• Changed logic for null/eol checks (#160).
  • only check once for "not at end of line"
  • check for null before we check for newline characters (the
    previous patch would fail for NULL + CR)
• Fix by not advancing past both \0 and \n (Yuki Izumi).
• Add test for NUL-LF sequence (Yuki Izumi).
• Fix memory leak in list parsing (Yuki Izumi).
• Use cmark_mem to free where used to alloc (Yuki Izumi).
• Allow a shortcut link before a ( (commonmark/commonmark-spec#427).
• Allow tabs after setext header line (commonmark/commonmark.js#109).
• Don't let URI schemes start with spaces.
• Fixed h2..h6 HTML blocks (commonmark/commonmark-spec#430). Added regression test.
• Autolink scheme can contain digits (Gábor Csárdi).
• Fix nullary function declarations in cmark.h (Nick Wellnhofer).
  Fixes strict prototypes warnings.
• COPYING: Update file name and remove duplicate section and
  (Peter Eisentraut).
• Fix typo (Pavlo Kapyshin).