remove network pause

Add optional parameter to Worker constructor for sleep period.
fix client repeat-disconnect loop.
removed resolver from getifaddr dance (not reqd) and updated getifaddr code (needs windowz/linux testing).
don't accept new connections if listenport bind fails (possible due to OS firewall settings).
only use upnp w/ipv4 addresses.
re: disconnect loop. Looks like ethhost session isn't deallocating once stopped. Thinking UI might have shared_ptr. For now, letting dealloc/quit continue as long as isOpen returns false -- maybe okay since network will be halted. Also, it maybe possible the issue is due to network thread not running after disconnect so packets aren't tx/rx to kill peer -- either way, it's possible remote end doesn't ack disconnect and timeout/force-close-dealloc is required, so will need more attention later.
Agreed, work in progress. With functionality separated out it's difficult to see what's breaking, what is redundant, and overall lifecycle. This will be done as a part of refactoring and might end up in another class. In it's current form, we can be sure that these methods aren't run out of sequence.