hdtest: Clean up entry names and help message

hdtest/comp_helper.c

@@ -60,7 +60,7 @@ json_t* dump_header_table(nghttp2_hd_context *context)
   if(context->role == NGHTTP2_HD_ROLE_DEFLATE) {
     json_object_set_new(obj, "localSize",
                         json_integer(context->local_hd_table_bufsize));
-    json_object_set_new(obj, "localMaxSize",
+    json_object_set_new(obj, "maxLocalSize",
                         json_integer(context->local_hd_table_bufsize_max));
   }
   return obj;

hdtest/deflatehd.c

@@ -47,7 +47,7 @@ static void output_to_json(nghttp2_hd_context *deflater,
   json_object_set_new(obj, "seq", json_integer(seq));
   json_object_set_new(obj, "inputLen", json_integer(inputlen));
   json_object_set_new(obj, "outputLength", json_integer(len));
-  json_object_set_new(obj, "PercentageOfOriginalSize",
+  json_object_set_new(obj, "percentageOfOriginalSize",
                       json_real((double)len / inputlen * 100));
   to_hex(hex, buf, len);
   json_object_set_new(obj, "output", json_pack("s#", hex, len * 2));

hdtest/inflatehd.c

@@ -146,7 +146,7 @@ static void print_help(void)
          "Reads JSON array from stdin and outputs inflated name/value pairs\n"
          "in JSON array.\n"
          "The element of input array must be a JSON object. Each object must\n"
-         "have following key:\n"
+         "have at least following key:\n"
          "\n"
          "    output: deflated header block in hex-string.\n"
          "\n"