fb55/htmlparser2 — pull request #107 by sailxjx (2014-10-23 04:45:07+00:00)
Title: use entry:content if entry:summary is not exist

According to [RFC4287](http://tools.ietf.org/html/rfc4287#section-4.1.1.1), most atom:entry element may not contain a summary field, e.g: https://github.com/blog.atom.
So use entry:content if entry:summary is not exist please.