V1 bsocial-comments

DO NOT MERGE!
==============

https://github.com/GigaOM/gigaom/issues/4475

Also:
https://github.com/GigaOM/gigaom/issues/4477
https://github.com/GigaOM/gigaom/issues/4476
https://github.com/GigaOM/gigaom/issues/4478
https://github.com/GigaOM/gigaom/issues/4633
@misterbisson Question about this after some testing I did today. Without the `s` modifier this doesn't find short codes that are wrapped around multiple lines of text.  Is this on purpose?  I could see this behavior confusing the editorial team.