If we have 9 joining members (starting simultaneously) and 1 operational member X, and
num_initial_rsps=5 and
timeout=3000

,then a joining member might receive 5 responses from other joining clients and not the one from the existing member.

This is good when we have initial concurrent startups, but not when we have existing 'well-known' operational members running.

FEATURE: add a flag 'ignore-client-responses' which will collect only responses from operational members (servers). In the above case, each joining member will either get a response from X, or time out after 5 secs. We could also define a min_operational_resps, which (enabled if > 0) defines the minimum number of responses which need to be received from operational member and ignores responses from client members.

WORKAROUND: increase num_initial_mbrs and timeout