* Add new config about knowledge distillation for query binary classifier
* remove inferenced result in knowledge distillation for query binary classifier
* Add AUC.py in tools folder
* Add test_data_path into conf_kdqbc_bilstmattn_cnn.json
* Modify AUC.py
* Rename AUC.py into calculate_AUC.py
* Modify test&calculate AUC commands for Knowledge Distillation for Query Binary Classifier
* Add cpu_thread_num parameter in conf.training_params
* Rename cpu_thread_num into cpu_num_workers
* update comments in ModelConf.py
* Add cup_num_workers in model_zoo/advanced/conf.json
* Add the description of cpu_num_workers in Tutorial.md
* Update inference speed of compressed model
* Add ProcessorsScheduler Class
* Add license in ProcessorScheduler.py
* use lazy loading instead of one-off loading
* Remove Debug Info in problem.py
* use open instead of codecs.open
* update the inference of build dictionary for classification
* add md5 function in common_utils.py
* add merge_encode_* function
* update typo
* update typo
* reorg the logical flow in train.py
* remove dummy comments in problem.py
* add encoding cache mechanism
* add lazy-load mechanism for training phase
* enumerate problem types in problem.py
* remove data_encoding.py
* add lazy load train logic
* Modify comment and remove debug code
* Judge if test_path exists
* fix parameter missing when use char embedding
* merge master
* add file_column_num in problem.py
* merge add_encoding_cache branch
* add SST-2 in .gitignore
* merge master
* use steps_per_validation instead of valid_times_per_epoch
* Fix Learning Rate decay logic bug
* add log of calculating md5 of training data
* fix multi-gpu char_emb OOM problem & add char leval fix_lengths
* Modify batch_num_to_show_results in multi-gpu
* Modify batch_num_to_show_results
* delete deepcopy in get_batches
* add new parameters chunk_size and max_building_lines in conf and update tutorials