Pin cider to stable version and introduce way of using own color theme

Unfortunately I didn't commit this in a way to seperate out changes to my user specific configs. But the gist of this PR is that it specifies that we should use `cider` and `clojure-mode` from **melpa-stable** instead of **melpa**. 

It also will check to see if the user's config sets `user-specific-color-theme` to a value and will use that instead of zenburn when loading the initial color theme.