feat(task): acknowledge the user what urls have been changed

When using this task, I would like to see exactly what urls have been changed just like other grunt tasks. Especially work with grunt-usemin, the blocks are replaced so the scripts are not cdnified and this might confuse users. google-cdn needs to be modifed so also submitted a PR there https://github.com/passy/google-cdn/pull/22
Oh, I see. I still find it a bit confusing. My brain shuts down when there's invalid HTML that I'm supposed to read. ;)
What do you think about just `"scripts/oldieshim.js" changed to "scripts/oldieshim.a466b7b1.js"`?