added copyright message in files (#2101)

src/treelearner/data_partition.hpp

+/*!
+ * Copyright (c) 2016 Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License. See LICENSE file in the project root for license information.
+ */
 #ifndef LIGHTGBM_TREELEARNER_DATA_PARTITION_HPP_
 #define LIGHTGBM_TREELEARNER_DATA_PARTITION_HPP_
 

src/treelearner/feature_histogram.hpp

+/*!
+ * Copyright (c) 2016 Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License. See LICENSE file in the project root for license information.
+ */
 #ifndef LIGHTGBM_TREELEARNER_FEATURE_HISTOGRAM_HPP_
 #define LIGHTGBM_TREELEARNER_FEATURE_HISTOGRAM_HPP_
 

src/treelearner/feature_parallel_tree_learner.cpp

+/*!
+ * Copyright (c) 2016 Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License. See LICENSE file in the project root for license information.
+ */
 #include <cstring>
 #include <vector>
 

src/treelearner/gpu_tree_learner.cpp

+/*!
+ * Copyright (c) 2017 Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License. See LICENSE file in the project root for license information.
+ */
 #ifdef USE_GPU
 
 #include "gpu_tree_learner.h"

src/treelearner/gpu_tree_learner.h

+/*!
+ * Copyright (c) 2017 Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License. See LICENSE file in the project root for license information.
+ */
 #ifndef LIGHTGBM_TREELEARNER_GPU_TREE_LEARNER_H_
 #define LIGHTGBM_TREELEARNER_GPU_TREE_LEARNER_H_
 

src/treelearner/leaf_splits.hpp

+/*!
+ * Copyright (c) 2016 Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License. See LICENSE file in the project root for license information.
+ */
 #ifndef LIGHTGBM_TREELEARNER_LEAF_SPLITS_HPP_
 #define LIGHTGBM_TREELEARNER_LEAF_SPLITS_HPP_
 

src/treelearner/ocl/histogram16.cl

-// this file can either be read and passed to an OpenCL compiler directly,
-// or included in a C++11 source file as a string literal
+/*!
+ * Copyright (c) 2017 Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License. See LICENSE file in the project root for license information.
+ *
+ * \brief This file can either be read and passed to an OpenCL compiler directly,
+ *        or included in a C++11 source file as a string literal.
+ */
 #ifndef __OPENCL_VERSION__
 // If we are including this file in C++,
 // the entire source file following (except the last #endif) will become

src/treelearner/ocl/histogram256.cl

-// this file can either be read and passed to an OpenCL compiler directly,
-// or included in a C++11 source file as a string literal
+/*!
+ * Copyright (c) 2017 Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License. See LICENSE file in the project root for license information.
+ *
+ * \brief This file can either be read and passed to an OpenCL compiler directly,
+ *        or included in a C++11 source file as a string literal.
+ */
 #ifndef __OPENCL_VERSION__
 // If we are including this file in C++,
 // the entire source file following (except the last #endif) will become

src/treelearner/ocl/histogram64.cl

-// this file can either be read and passed to an OpenCL compiler directly,
-// or included in a C++11 source file as a string literal
+/*!
+ * Copyright (c) 2017 Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License. See LICENSE file in the project root for license information.
+ *
+ * \brief This file can either be read and passed to an OpenCL compiler directly,
+ *        or included in a C++11 source file as a string literal.
+ */
 #ifndef __OPENCL_VERSION__
 // If we are including this file in C++,
 // the entire source file following (except the last #endif) will become

src/treelearner/parallel_tree_learner.h

+/*!
+ * Copyright (c) 2016 Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License. See LICENSE file in the project root for license information.
+ */
 #ifndef LIGHTGBM_TREELEARNER_PARALLEL_TREE_LEARNER_H_
 #define LIGHTGBM_TREELEARNER_PARALLEL_TREE_LEARNER_H_
 

src/treelearner/serial_tree_learner.cpp

+/*!
+ * Copyright (c) 2016 Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License. See LICENSE file in the project root for license information.
+ */
 #include "serial_tree_learner.h"
 
 #include <LightGBM/network.h>

src/treelearner/serial_tree_learner.h

+/*!
+ * Copyright (c) 2016 Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License. See LICENSE file in the project root for license information.
+ */
 #ifndef LIGHTGBM_TREELEARNER_SERIAL_TREE_LEARNER_H_
 #define LIGHTGBM_TREELEARNER_SERIAL_TREE_LEARNER_H_
 

src/treelearner/split_info.hpp

+/*!
+ * Copyright (c) 2016 Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License. See LICENSE file in the project root for license information.
+ */
 #ifndef LIGHTGBM_TREELEARNER_SPLIT_INFO_HPP_
 #define LIGHTGBM_TREELEARNER_SPLIT_INFO_HPP_
 

src/treelearner/tree_learner.cpp

+/*!
+ * Copyright (c) 2016 Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License. See LICENSE file in the project root for license information.
+ */
 #include <LightGBM/tree_learner.h>
 
 #include "gpu_tree_learner.h"

src/treelearner/voting_parallel_tree_learner.cpp

+/*!
+ * Copyright (c) 2016 Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License. See LICENSE file in the project root for license information.
+ */
 #include <LightGBM/utils/common.h>
 
 #include <cstring>