More indication of task sequencing in interface.

[damellis]

This doesn't necessarily need to involve large changes, but it would be good to provide more guidance as to the sequence of steps the user needs to take. For instance, after they collect calibration data, we might have a button for "proceed to training" #120. The training tab might have some statement that suggests when to train the model ("Once you've collected some training data, train the model and see how it performs.") Etc.