chjj/marked — pull request #178 by tasuk (2013-06-18 21:47:58+00:00)
Title: Improve smartypants support

Taken from http://gist.github.com/drdrang/705071

Basically, if a ' or a " is preceded by the beginning of line, dash,
slash, parentheses, brackets, quotes, or whitespace, it's an opening
one. Otherwise it's a closing one.