Convert some prints to addDetails calls.

If instead of using print, we use testtools details, we can capture the data
sensibly in the subunit output stream. That way, we can make good display
decisions about the data to be shown in the HTML reports as needed.

Part of blueprint grizzly-testtools

Change-Id: I125b0bf60591ec3c854aa757b370a1c3573a40d2
Merge "Convert some prints to addDetails calls."