Created by: sidgoyal78

This addresses issue #7972 (closed).

The python side save_vars was modified to check for correctness. The python side of load_inference_program is being modified by @kexinzhao as part of #7959 (closed). The load_vars in the current PR is incorrect, but is not useful for the current task. We just need a working save_vars version, which is working with the changes in this PR.

I have tested the correctness of this PR by saving a model on the python side, and then running the example.

Another thing that came up while testing and discussing with @kexinzhao offline, is that we need to keep the ordering of params consistent in both python and c++ side for using the new load_combine and save_combine ops.