Big refactor of command handling, big payloads now correctly handled

[divmgl]

No description provided.

[divmgl]

For anyone who is wondering about the technical side of this:

createCommandHandler was previously handling the chunks processing. This is incorrect because createCommandHandler is only invoked once all of the chunks are available. The code that involved a recursive call was removed because it would only ever be invoked once, and most of the buffering code was moved to the parent: the response event handler.

The next issue is that the response event handler was not buffering data correctly in multipart scenarios. Essentially, if an incoming data chunk did not have a \r\n, undefined would be sent to the command handler. This implementation continues to fill the buffer until it reaches a \r\n. If it reaches a \r\n and it's a multipart command, it will store the first result, clear the buffer, fill the buffer a second time until it reaches \r\n, then send both the previous pending command result and the payload over to the command handler.