Retrieval Deal Testground test plan

[adlrocha]

As part of our efforts on 3DMs, one of the first things we focused on is on building a testing harness to profile the performance of different retrieval implementations. Initially, our focus has been mainly on the client metering part. So far what we have is:

• A fork of Lotus in which the lotus-soup test plans have been updated to make it work with recent versions of the code including a new retrieval test case, and with an additional API function ClientRetrievalStat to gather more fine-grained metrics from the retrieval process.

• A fork of go-fil-markets which adds an additional CollectStats function in the environment to enable the gathering of metrics in client_fsm so that we can measure the performance and extract any metric from the different stages in a retrieval. This code could be generalized so this CollectStats can be used in any FSM throughout the Filecoin code base.

• The go-fil-markets fork also includes in the docs some preliminary designs for the state-machines of the RFCs proposed so far in the 3DM Open problem.

(Posting this progress update here so we don't forget and for others to build upon it)