Fix setup.sh for mavericks and latest HEAD(s).
Add flycheck-mode to things that can use it.
Setup yasnippet and add snippets for c-mode.

Also testing out clang-format.
I'm a dork, accidentally commited some of this prior to a good time.

Meh, just amending the commit message. No big deal.
Add some more snippets for c-mode.
add linum mode for cc-mode