How to render, upload and download large files on heroku with s3 huangzhimin.com
it's my new blog post, http://huangzhimin.com/2013/06/18/how-to-upload-and-download-large-files-on-heroku-with-s3/
time_ago_in_words to calculate the time distance, but it's not good, we should use client side solution instead, Not use time_ago_in_words