[PATCH 0/9] MR1196: winsock: Implement SO_EXCLUSIVEADDR.

[Paul Gofman (＠gofman)]

While adding tests for this I also find a couple of things related to previous MR 1111 which I am also fixing here:
- it turns out IPV6 loopback (as in "::1") should not be mapped to ipv4-mapped loopback, ipv6 and ipv4 loopbacks are different addresses. The mapping of that was also missing htonl() for INADDR_LOOPBACK so essentially didn't break anything;
- basically the same is for INADDR_ANY (ipv6 "any" doesn't prevent binding to ipv4 "any"), although that is different when SO_EXCLUSIVEADDRUSE is used: in that case ipv6 wildcard address actually blocks ipv4 INADDR_ANY.