Created by: wangjiawei04

1. implement C++ General DistKVOp

2. add sparse criteo demo

3. core/predictor/framework/quant.cpp is the implementation of compressing model and generate Hadoop Sequence File. Usage: write_seq(file1, file2, 8, 8) it means the Sparse Param File (file1), will be converted to Sequence File (file2), the quant bits is 8 and the thread pool size is 8.

still developing