Replace sanityinc with jcf

I'm removing mention of sanityinc because I want my Emacs config inside
my own namespace.

Making this change was so simple with a bit of `ag` and `wgrep`.

The process went something like:

1. Search for all occurrences of sanityinc in the emacs.d directory
1. Switch to the `*ag*` buffer
1. Activate `wgrep-change-to-wgrep-mode`
1. %s/sanityinc/jcf/g
1. C-x C-s

Wow.