- Made the SOCKS code use the new Curl_read_plain() function to fix the bug

Markus Moeller reported: http://curl.haxx.se/mail/archive-2008-09/0016.html

- recv() errors other than those equal to EAGAIN now cause proper
  CURLE_RECV_ERROR to get returned. This made test case 160 fail so I've now
  disabled it until we can figure out another way to exercise that logic.

lib/socks.c

@@ -88,7 +88,7 @@ static int blockread_all(struct connectdata *conn, /* connection data */
       result = ~CURLE_OK;
       break;
     }
-    result = Curl_read(conn, sockfd, buf, buffersize, &nread);
+    result = Curl_read_plain(sockfd, buf, buffersize, &nread);
     if(result)
       break;