RubaXa/Error.stack — pull request #1 by PeterDaveHello (2014-07-10 07:52:42+00:00)
Title: use protocol-relative URL to load libraries

browser will tell users that the page contains some insecure resources, use protocol-relative URL can prevent this issue.

reference : [The Protocol-relative URL](http://www.paulirish.com/2010/the-protocol-relative-url/)