Clean up imports in deepdisc.py

[drewoldag]

This work should only happen after the Informer and Estimator stages are stable.

There were a lot of imports that were added when experimenting with the code, that are no longer used.

The complicating factor here is that there is some code that is commented out, and as such, it's hard to tell which imports are used but commented out, versus those that truly unnecessary.