This makes it easier to debug state mismatches by providing a nice way
to figure out which actors differ between two state-trees and
how (balance, nonce, state, etc.).
It doesn't provide a way to actually _diff_ those state-trees, but one
can use `lotus chain get` to figure that out (although it would be
_nice_ to provide something a bit smarter).
Steven Allen
e89f7d9023