added output_freq to aliases (#1169)

* add output_freq to aliases

* reordered params set according to review comment

docs/Parameters.rst

@@ -602,7 +602,7 @@ Metric Parameters
 
    -  support multi metrics, separated by ``,``
 
--  ``metric_freq``, default=\ ``1``, type=int
+-  ``metric_freq``, default=\ ``1``, type=int, alias=\ ``output_freq``
 
    -  frequency for metric output
 

include/LightGBM/config.h

@@ -468,13 +468,13 @@ struct ParameterAlias {
       "pred_early_stop_margin", "use_missing", "sigmoid",
       "fair_c", "poission_max_delta_step", "scale_pos_weight",
       "boost_from_average", "max_position", "label_gain",
-      "metric", "metric_freq", "time_out",
+      "metric", "output_freq", "time_out",
       "gpu_platform_id", "gpu_device_id", "gpu_use_dp",
       "convert_model", "convert_model_language",
       "feature_fraction_seed", "enable_bundle", "data_filename", "valid_data_filenames",
       "snapshot_freq", "verbosity", "sparse_threshold", "enable_load_from_binary_file",
       "max_conflict_rate", "poisson_max_delta_step", "gaussian_eta",
-      "histogram_pool_size", "output_freq", "is_provide_training_metric", "machine_list_filename", "machines",
+      "histogram_pool_size", "is_provide_training_metric", "machine_list_filename", "machines",
       "zero_as_missing", "init_score_file", "valid_init_score_file", "is_predict_contrib",
       "max_cat_threshold",  "cat_smooth", "min_data_per_group", "cat_l2", "max_cat_to_onehot",
       "alpha", "reg_sqrt"