use protocol-relative URL to load resources

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/)
Merge pull request #88 from PeterDaveHello/patch-1

use protocol-relative URL to load resources
Merge branch 'master' of github.com:RubaXa/jquery.fileapi
Merge branch 'gh-pages'