* Add debug logs in scope, meta_cache and memory

* Add missing deps

Comment out `test_lstm_unit_op` test.

Add merge model scripts

Add pool2d cudnn op

* fix compile error

* remove unittest

* disable huber loss unittest

add logs and fix a python path bug

refine check macro

add Max strategy for sequence_pool op

Add huber loss operator.

Auc op

fix ft job converge

* Adding L1 norm op for L1 regularization

* Addressing code review feedback

* Address code review feedback

* Change variable names to match google style guide

* Op developer can add `InferShape` to any operator

* add sparse support for sum op

* typo fix

* fix gpu build error

* fix unittest error

* typo fix

* infer var type and shape in op_test

* follow comments

* fix build error

* bypass some unittests depend on NetOp

* Python API for save/load variables

* Polish names