Dynamic Plugin Installation

[toastercup]

Engineers wishing to prop up their own Cortex instance shouldn't have to modify core, and installation of plugins in a SaaS environment should be self-service. To accomplish this, we cannot rely on the standard Bundler implementation - we'll have to get dynamic!

Let's use this issue to map out potential solutions. Some places to start:

• https://stackoverflow.com/questions/8492547/loading-gem-at-runtime-in-rails-3
• https://gist.github.com/adamjmurray/3154437