Currently user plugins have to be compiled along with Fierro. Also, they have to be written inside of the Fierro repository. Additionally, users writing such plugins have limited help in testing/debugging them.

We should create a small framework for our plugins that supports:

1. Independent compilation
2. Independent testing
3. Consistent interface across plugin locations (not terribly relevant now, as we have very few plugin hook locations. But likely relevant as we add more user controls).