MB-22215: Always accept username and password but deprecate them
MB-22215: Always accept username and password but deprecate them

couchbase-cli in previous version always required a username and
password for connecting to the cluster, but this was not needed
for some commands. In order to support backward compatibility we
will hide the options from the command line and report that they
are deprecated if they are entered.

Change-Id: I8040831f1aae6574598cb911a941573dd5832795
Reviewed-on: http://review.couchbase.org/72202
Reviewed-by: Michael Wiederhold <a17fed27eaa842282862ff7c1b9c8395a26ac320@couchbase.com>
Tested-by: Michael Wiederhold <a17fed27eaa842282862ff7c1b9c8395a26ac320@couchbase.com>

couchbase/couchbase-cli,couchbase/couchbase-cli