Fix bug #2808

Add explicit text/html and text/xml to the accepts header.  Move PNG
to the from of the list of accepted image formats.

network/protocol/http/mkhttp.c

@@ -1402,11 +1402,11 @@ net_build_http_request (URL_Struct * URL_s,
             if(CLEAR_CACHE_BIT(format_out) != FO_INTERNAL_IMAGE)
             {
                 /* send Accept: *(slash)* as well as the others */
-                sprintf(line_buffer, "Accept: %s, %s, %s, %s, %s, */*" CRLF, 
+                sprintf(line_buffer, "Accept: %s, %s, %s, %s, %s, %s, %s, */*" CRLF, 
-                    IMAGE_GIF, IMAGE_XBM, IMAGE_JPG, IMAGE_PJPG, IMAGE_PNG);
+                    TEXT_HTML, TEXT_XML, IMAGE_PNG, IMAGE_GIF, IMAGE_XBM, IMAGE_JPG, IMAGE_PJPG);
             } else {
                 sprintf(line_buffer, "Accept: %s, %s, %s, %s, %s" CRLF, 
-                    IMAGE_GIF, IMAGE_XBM, IMAGE_JPG, IMAGE_PJPG, IMAGE_PNG);
+                    IMAGE_PNG, IMAGE_GIF, IMAGE_XBM, IMAGE_JPG, IMAGE_PJPG);
             }
 
             tmpSize = PL_strlen(line_buffer);