use git submodules for vendor files

[jackfranklin]

Or potentially use something like Twitter's Bower, so they can easily be updated?

Past experiences with submodules have never been brilliant for me, personally. They seem more trouble than they are worth - although perhaps that's me not fully understanding them.

[jcsrb]

agreed, Bower might be a better way, further research into submodules showed why they are tricky http://codingkilledthecat.wordpress.com/2012/04/28/why-your-company-shouldnt-use-git-submodules/