Previously, we only returned the first result that looked like an IPv6
or IPv4 address.
This cropped up when attempting to connect to https://cxbyte.me/ whilst
IPv6 on the server wasn't working. Since we only returned the first
result, which happened to be the IPv6 address, we wasn't able to
connect.
Returning all results allows curl to attempt to connect to a different
IP if one of them isn't working, and potentially make a successful
connection.
The "ready to write" notifier we set up in generic socket connection is
really only meant to detect a successful connection. Once we have a TCP
connection, for example, it will fire on every event loop iteration.
This was causing IRC Client to max out the CPU by getting this no-op
notifier callback over and over.
Since this was only used by TLSv12, I changed that code to create its
own notifier instead. It might be possible to improve TLS performance
by only processing writes when actually needed, but I didn't look very
closely at that for this patch. :^)
