[0.16]

  * Improved regex for HTML comments (#263).
  * Fixed CDATA regex (#267).
  * Use linked list instead of arrays in AST: the same doubly linked
    node structure as cmark uses.  This simplifies some code and
    eliminates the need for recursive algorithms, so we can render
    deeply-nested structures without stack overflows.
  * Use `children` instead of `label` (in Image and Link),
    `inline_content` (in Paragraph), and `c` (in Emph and Strong).
  * Renamed the `c` property to `literal` to match `libcmark`.
  * Use `literal` rather than `string_content` property for code
    blocks, HTML.  `string_content` is reserved for raw string
    content that has yet to be parsed as inlines.
  * Improved end lines (#276).
  * Added a node walker, for easy AST traversal (see `node.js`).
  * Regularized position information into a `sourcepos` property.
    Added end column information.
  * Renamed `html-renderer.js` to `html.js`.
  * Replace NUL characters with U+FFFD, as per spec.
  * Optimized code, resulting in significant performance gains.
    (We've gone from being twice as fast as showdown.js to being
    three times as fast, on par with marked.)
  * Made `tight` a property of `list_data` rather than `Node`.
  * Added options to renderer, parser objections.
  * Added a `--sourcepos` command line option to `js/bin/commonmark`.
  * HTML renderer now throws an error on unknown tag type (which
    indicates a programming error).
  * Removed `ansi.js` code from the source tree. The test suite now
    uses its own mini ansi colors implementation.
  * Added `--time` option to `js/bin/commonmark`.
  * Added an XML renderer (XML representation of the AST, matching
    `Commonmark.dtd`).
  * Changed `url` property to `destination` to match `cmark` and spec.
  * Added `js/common.js` to hold some common code, like string
    unescaping and URI normalization.
  * Use `decodeURI` instead of `unescape`.
  * Added some "pathological" test cases to test suite.