BUG/MEDIUM: mcli: Properly handle errors and timeouts during reponse processing

BUG/MEDIUM: mcli: Properly handle errors and timeouts during reponse processing

The response analyzer of the master CLI only handles read errors. So if
there is a write error, the session remains stuck because some outgoing data
are blocked in the channel and the response analyzer waits everything to be
sent. Because the maxconn is set to 10 for the master CLI, it may be
unresponsive if this happens to many times.

Now read and write errors, timeouts and client aborts are handled.

This patch should solve the issue #1512. It must be backported as far as
2.0.