Don't specifiy protocol for external libraries

Fixes mixed content in Firefox >= 23.
https://blog.mozilla.org/tanvi/2013/04/10/mixed-content-blocking-enabled-in-firefox-23/
https://developer.mozilla.org/en-US/docs/Security/MixedContent
Merge pull request #2 from sonnyp/patch-1

Don't specifiy protocol for external libraries
Merge branch 'master' into gh-pages
Add github search capability
Fix preformat bug