Undoes auto-complete on request from @amohammadi

On a request from @amohammadi claiming slowness and problems with his bash/zsh setup, I removed this contributions in this MR.

To surmount slowness, we'd have to re-write some of our cmdline apps to take that into account, avoiding excessive imports.

To issues with zsh/bash setup could be circumvented with a more clever set of activation/deactivation scripts.

Fixes #70 (closed)