* reduce trainer count for unit test on MAC OSX

* Fix lots of trainer_config_helpers bug, and complete unittest for `layers.py`

* Correctly handling multiple inputs and integer inputs for recurrent_group

* Fix ScatterAgentLayer for generation

* Revert sequence_(nest)_rnn.conf

* Add `device` parameter to ExtraAttr in trainer_config_helpers.
* add unittest for it.

* add type compatible check for ParamAttr

Local training with "sparse_update = True" parameter triggers kSgdSparseCpuTraining mode, fix bugs under it.

fix cudnn conv bug which occurs in image classfication demo in GTX GPU

* Also refine unittest to multiple iteration to prevent luckily random number.

* fix bug in dotmul_operator's api and anotation
* update rnn document
* remove redundant info of projection and operator in layers.py

* it makes unit test failed.

* using map to replace unordered_map on Mac

* remove unnecessary field set in ParameterConfig, Evaluators, etc

update beam_search and seqToseq config, and add ExpActivation api

* split dotmul_projection and dotmul_operator
* bug fix in outputsize checking for mixed layer

* min_pool_size would be infinite by default.
  * add unittest for min_pool_size
* Fix bug in can_over_batch_size
  * add unittest for can_over_batch_size
* Add DEFINE_PROVIDER_EX
* Add default value of should_shuffle
  * When training, the default value of should_shuffle is True.
  * When testing, the default value of should_shuffle is False.
  * User a set a provider should_shuffle or not by pass it to `@provider`
  * should_shuffle can handle a list of value, not just boolean
* Add input order mapping by using name
  * Add unittest
* Add check to check input format.
  * Default is close for speed reason.
  * User could stop train when check error, or continue train without
    this train sample.
* use deque instead of vector in generators pool, make erase
  generator faster.
* Add chinese/english documentation
* Make should shuffle = false in unittest
* Add python files to depends.

Add findZLIB in cmake

* Also fix a bug, we should link -ldl at last