Manage the entire Docker chain life-cycle with the server app

[lkwdwrd]

When I wrote the player/orchestra objects for controlling the docker containers, I imagined something much greater than simply starting up the containers. The intent was the ability to track each chain's life-cycle and have the ability to access specific pieces as needed.

Right now once the chain is created, the Server app basically forgets about the chain objects used to start it and only worries about what is stored in the mapping files. I would like to see this modified to the point where the server app keeps hold of the chain in memory and saved out to a file as needed. This will allow us to do a proper shutdown of the containers when we exit, as well as a proper start up of the chains. Right now we simply make a lot of assumptions about what's available in Docker and handle errors if it doesn't do what we expect.

Instead of making all these assumptions, I'd like to keep track of our chains and make use of them.