Created by: Meiyim

A new high level API for paddle, featuring:

1. Train and eval with model_management
2. auto WarmStart
3. Hyper param & run_config management
4. Customize-able dataset pipeline (build on fluid.layers.py_reader, not efficient but can cover most of the use case)
5. High level dataset builder FeatureColumn. (build input pipeline with a few lines of code)
6. Fancy summary visualization(with tensorboard)