Negotiate: custom service names for SPNEGO.

* Add new options, CURLOPT_PROXY_SERVICE_NAME and CURLOPT_SERVICE_NAME.
* Add new curl options, --proxy-service-name and --service-name.

include/curl/curl.h

@@ -1632,6 +1632,12 @@ typedef enum {
   /* Do not squash dot-dot sequences */
   CINIT(PATH_AS_IS, LONG, 234),
 
+  /* Proxy Service Name */
+  CINIT(PROXY_SERVICE_NAME, OBJECTPOINT, 235),
+
+  /* Service Name */
+  CINIT(SERVICE_NAME, OBJECTPOINT, 236),
+
   CURLOPT_LASTENTRY /* the last unused */
 } CURLoption;
 

include/curl/typecheck-gcc.h

@@ -270,6 +270,8 @@ _CURL_WARNING(_curl_easy_getinfo_err_curl_slist,
    (option) == CURLOPT_DNS_LOCAL_IP4 ||                                       \
    (option) == CURLOPT_DNS_LOCAL_IP6 ||                                       \
    (option) == CURLOPT_LOGIN_OPTIONS ||                                       \
+   (option) == CURLOPT_PROXY_SERVICE_NAME ||                                  \
+   (option) == CURLOPT_SERVICE_NAME ||                                        \
    0)
 
 /* evaluates to true if option takes a curl_write_callback argument */