Don't warn when setsockopt(SO_REUSEABLE) on accept()ed socket says EINVAL

This should fix bug10081.  I believe this bug pertains to OSX
behavior, not any Tor behavior change.
Extract code to handle RESOLVED cells

No other changes have been made; only code has been moved.
Look at all of a RESOLVED cell; not just the first answer.

Also, stop accepting the old kind of RESOLVED cells with no TTL
fields; they haven't been sent since 0.1.1.6-alpha.

This patch won't work without the fix to #10468 -- it will break
DNSPorts unless they set the proper ipv4/6 flags on entry_connection_t.
Tests for resolved_cell_parse
Unit tests for connection_edge_process_resolved_cell

Also rename a function to be more accurate (resolve->resolved)
Merge remote-tracking branch 'public/bug10081'