"fooport auto" should be able to get a hint

In #3945 (closed) we learned that "socksport auto" (as implemented in #3076 (moved)) on Windows is confusing users who use external applications that expect Tor to be listening on port 9050. The "fix" was to disable using auto ports in the TBB 0.2.2 Windows bundles.

A better answer to this issue is to

A) teach Tor how to remember which port it used last time, and try that one first (#3511 (moved))

B) seed it with our favorite port, e.g. by setting another config option like "SocksPortPreferred 9050". Maybe it would try both the preferred port and the one it picked last time, in some order. My first thought is that it should try the previous one first, and fall back to the configured preference before falling back to a random high-numbered port.

If we want to get fancier, we could make the prefered list be a 'schedule' of ports to try, e.g. for ORPortPreferred it could be "443,80".

Picking a more normal port should also help the Comodo firewall users in #3941 (closed) who are being blocked from reaching their high-numbered port.