**WARNING - Backwards compatibility changes:**
* 167: For practical reasons and for following common packaging practices, `contrib` folder got moved under the `mistletoe` folder / package. So if you reference a renderer from that folder, you need to reference it as `mistletoe.contrib.<renderer>` now.
* See "change handling of (white)space characters in code spans" below. We keep processing extra whitespace characters at the parsing level, so that all renderers can benefit from it out-of-the-box. Provided that a custom renderer, for whatever reason, relied on all the spaces being collapsed, it needs to do that collapsing itself now (e.g. `' '.join(re.split('[ \n]+', content.strip()))`, or `re.sub('[ \n]+', ' ', content.strip())`).
**Added:**
* `JIRARenderer`: Support link title notation, i.e. `[label](url "title")` gets transformed to `[label|url|title]` (161)
**Fixed:**
* Make the `traverse()` function actually work with various input parameters:
* filtering by class (157, 158)
* filtering by `depth` (159)
* Compatibility with the latest CommonMark specification v0.30 (108):
* Change handling of (white)space characters in code spans (156; in line with commonmark/commonmark-spec532 and commonmark/commonmark-spec569)
* Fix handling of tabs and parsing continuation lines within list items (89 via 164)
* Fix the other examples, mostly edge cases, from the spec (see 165 and 168 for details; 173 seems to be fixed as well)
* Make parsing of link reference definitions (a.k.a. `Footnote`s) more strict - spec compliant (132)
* Fix handling of special punctuation characters when parsing emphasis (96, 175)
**Updated:**
* Smaller inner working refactorings, like 171.