functionality

#845247

connection to avoid re-use of it, since we cannot know in what state it is.

existing error is the one returned back

also removed very old "require libcurl older than blablabla"

argv test. This way, the default can be overridden better (for cross-compiles
etc)

properly bail out from, when using ares.

I guess it seldomly happens on linux and that's why it wasn't found before.
He used Solaris to notice it.

I took the opportunity to rewrite the Curl_connecthost() slightly to feature
less duplicate code in the two different versions (ipv4/ipv6).

This seems more appropriate, and I believe mozilla and the likes do this.

.html files now get text/html as Content-Type.

Pointed out in bug report #839806.

(at least).