Modified the default HTTP headers used by libcurl:

A) Normal non-proxy HTTP:

 - no more "Pragma: no-cache" (this only makes sense to proxies)

B) Non-CONNECT HTTP request over proxy:

 - "Pragma: no-cache" is used (like before)
 - "Proxy-Connection: Keep-alive" (for older style 1.0-proxies)

C) CONNECT HTTP request over proxy:

 - "Host: [name]:[port]"
 - "Proxy-Connection: Keep-alive"

tests/data/test61

@@ -46,7 +46,6 @@ http://%HOSTIP:%HTTPPORT/we/want/61 -c log/jar61.txt -H "Host: www.host.foo.com"
 </strip>
 <protocol>
 GET /we/want/61 HTTP/1.1
-Pragma: no-cache
 Accept: */*
 Host: www.host.foo.com