Cleanup bb.js and binary interface and document communication convention

[kevaundray]

Problem

Using info for stdout

Currently the implementation will use info for information relevant to the command in question. For example, in the GetNumberGates command, we print the number of using info.

info prints to stderr whereas in this case we want to print it to stdout.

Document methods

Since we need to have the bb.js binary and the bb binaries have the same conventions and interface, we should document the bb binary interface and have the bb.js binary version copy it and use the documentation as the reference.

We should also ideally have tests which check that these two binaries are the same. proofs are non-determinsitic, but for all other commands, we can simply just check that the output is the same.

Supporting stdout and file system communication

For some commands, we print to stdout/stderr like GetGates and for others we write to a file. We should standardize this and document. In my head, I think for any command which outputs to a file, we can have it also print the relevant data to stdout. I think we can iterate on this as we use the API.