* hide misc APIs

* update

* fix transformer test

* update API.spec

* fix the order of sum

* add doc

* check whether need to copy

* follow comments

* Added beam search API to fluid/contrib

* Change as review comments

* API.spec change

* Doc updated

* memory init

* add env

* refine anounce

* Add check for Nan

* Debug

* Add env for cc_test

* Add env for py_test and nv_test

* Remove py_test env

* Add env for py_test

* serial test_recognize_digits

* Test FLAGS_init_allocated_mem function for unit test

* Init allocated mem for op unit test

* Add env for all unit test

* "fix deterministic"

* "fix ci"

* "fix init"

2. remvoe comment line

* add lod_tensor utility python module

* add lod_tensor test code

* add more lod tensor tests

* modify word2vec example code using new api

* add comment

* fix trainer import error on ce

* fix setup.py.in

- The trainer and inferencer will load params from disk if param_path
  argument is not None in their constructor.

- Remove params.py, we will expose core.Scope to the user if needed
  (e.g., for GAN). Currently we will not expose it, unless we clearly
  know doing so can support GAN.

- Add `save_params` to Trainer (a TODO item).

- rename "network" to "program"

* "add metrics"

* "add fluid metrics"

* "add import guards"

* "show warnings"

* "add demo"

* "fix ci"

* "add some details"

* "fix cci"

* "add demo Python"

* "add metrics"