Reimplement ares_gethostbyname() by wrapping ares_getaddrinfo()

[bradh352]

ares_gethostbyname() and ares_getaddrinfo() do a lot of similar things, however ares_getaddrinfo() has some desirable behaviors that should be imported into ares_gethostbyname(). For one, it sorts the address lists for the most likely to succeed based on the current system routes. Next, when AF_UNSPEC is specified, it properly handles search lists instead of first searching all of AF_INET6 then AF_INET, it searches in parallel. Therefore, this PR should also resolve the issues attempted in #94.

A few things this PR does:

1. ares_parse_a_reply() and ares_parse_aaaa_reply() had very similar code to translate struct ares_addrinfo into a struct hostent as well as into struct ares_addrttl/ares_addr6ttl this has been split out into helper functions of ares__addrinfo2hostent() and ares__addrinfo2addrttl() to prevent this duplicative code.
2. ares_getaddrinfo() was apparently never honoring HOSTALIASES, and this was discovered once ares_gethostbyname() was turned into a wrapper, the affected test cases started failing.
3. A slight API modification to save the query hostname into struct ares_addrinfo as the last element of name. Since this is the last element, and all user-level instances of struct ares_addrinfo are allocated internally by c-ares, this is not an ABI-breaking change nor would it impact any API compatibility. This was needed since struct hostent has an h_name element.
4. Test Framework: MockServer tests via TCP would fail if more than 1 request was received at a time which is common when ares_getaddrinfo() queries for both A and AAAA records simultaneously. Infact, this was a long standing issue in which the ares_getaddrinfo() test were bypassing TCP alltogether. This has been corrected, the message is now processed in a loop.
5. Some tests had to be updated for overall correctness as they were invalid but somehow passing prior to this change.

[bradh352]

@ChristianAmmer, please review and see if this accomplishes your goal from PR #94

[bradh352]

If there's no comments, I'll probably just merge it and deal with the fallout. This blocks me from working on #429 & #399

[bagder]

I'll probably just merge it and deal with the fallout.

That's fine with me. I've started a review and it looks fine but I haven't managed to get through it all...

[ChristianAmmer-zz]

@bradh352 sorry for the late reply. Your PR accomplishes the goal from PR #94, thanks for taking care. I'm going to do a review, but I'm not that familiar with the code anymore.