Provide way to reload a single circuit

[scorfield]

There should be an easy way to reload a single circuit.

[scorfield]

This turns out to be rather dangerous. In development-full-load and development-circuit-load it isn't needed (because changed circuits are always reloaded and all requests are re-parsed). However, in production mode, if you reload a single circuit, you need to force a reparse of all fuseactions that access that circuit in any way, shape or form to ensure consistency.

I actually implemented this and started testing it and found all sorts of weird problems caused by inconsistencies between the new in-memory circuit and the various parsed fuseactions that used the circuit (only the requested fuseaction was consistent - other fuseactions were still based off the old circuit definition).

In production, you don't want to force re-parsing anyway.

There needs to be a better way to handle production deployment issues at some point.