Split the interface to change environments out from the minimal Backend
interface, to make it optional for backend implementations. If
backend.MultiState isn't implemented, return a "not implemented" from
environment related methods.
Have the Local backend delegate the MultiState methods to the proper
backend.
I made this interface way back with the original backend work and I
guess I forgot to hook it up! This is becoming an issue as I'm working
on our 2nd enhanced backend that requires this information and I
realized it was hardcoded before.
This propertly uses the CLIInit interface allowing any backend to gain
access to this data.
The local backend implementation is an implementation of
backend.Enhanced that recreates all the behavior of the CLI but through
the backend interface.
James Bardin