Fix endless moved redirections, connection leak and others

[orelmaliach]

1. Fix weird case where redis connection returns MOVED response to the same node from which the data was fetched- closing the TCP socket resolves the issue.
2. Fix a potential connection leak in case of node failure or cluster down.
3. Fix ASK redirection resulting in an extra redirection attempt.
4. Fix key in case of "eval" or "evalsha" command with 0 keys.
5. Fix handling of failure to parse ASK signal when it came from a pipeline result.
6. Refactor, reformat, fix typos.