Web configuration interface for the gui

As we're moving to a distributed setup, we're losing a lot of the GLUT features.

Ideally, we should still support the GLUT stuff by filling values into the scl GUI data structure, and send it to redis.

However, this can get a bit annoying if there are a lot of GLUT instances. For now, perhaps we should focus on a single robot use case and set things up. We can always generalize later (and this is likely to cover most of our existing ideas anyway).