Import Public Keys of Already-Tracked users

It would be super-handy (especially for those of us who stupidly delete our ~/.gnupg directory) if the keybase command line tool could import (preferably by bulk) they public keys of the Keybase users we are already tracking.

At the moment, it appears that the only way to locally import the public keys would be to un-track and then re-track each user.

Since I'm already tracking them, it seems like being able to import (maybe even sync?) public keys would be a cool next step.

Start with the Keybase command line tool and trace how tracking and local public-key import currently work. Define a bulk operation for users already being tracked, including whether it should sync keys, then verify that tracked users' public keys are restored without untracking and retracking each user.

Written by the indexing model from the issue text.