Add coverage data processing tools.

1. Add a new input named batch_roi_nums for prroi_pool_op. batch_roi_nums includes the number of roi for each image in batch when rois is Tensor. This information is saved in rois's lod when rois is LoDTensor.
2. add grad check to prroi_pool_op and solve unnormal X grad diff in CPU.

* fix sample code, test=develop

* polish code style, test=develop

* modify test framework, test=develop

* fix test_fsp_op, test=develop

* up, test=develop

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* add check for threshold, test=develop

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* update, test=develop

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test=develop

enhanced ops: acos, asin, brelu, ceil, cos, elu, floor, hard_shrink,
hard_sigmoid, hard_swish, relu6, round, rsqrt, sin, softshrink,
cos_sim, cross_entropy, im2squence, kldiv_loss

* enhance load interface; test=develop

* add uni test and add comment; test=develop

* fix converage; test=develop

* use path.joint replace "/"; test=develop

* windows debug; test=develop

* fix window unitest error; test=develop

* fix commet error; test=develop

* add model shuffix check; test=develop

* fix example error; test=develop

test=develop

* add TRT support for instance_norm op

windows conv_fusion failed as no kernel， explicit declare lambda
Signed-off-by: Nzhaoyuchen <zhaoyuchen01@baidu.com>

* support dygraph structured name; test=develop

* add load static param unitest and fix save load; test=develop

* fix varBase import error; test=develop

* fix unitest error; test=develop

* add comment for parameter; test=develop

* fix uni test error; test=develop

* change parallel se-resnet; test=develop

* fix dygraph se resnext parallel test; test=develop

* remove useless code; test=develop

* remove useless code; test=develop

* set esp as 1e-6 to solve elu unitest fail,test=develop

* add special way to add distribute vars， Update Pyramid hash op

* fix Variable's gradient api in framework.py, test=develop

* remove namescope, test=develop

* Fix the global_step & continuous applying error in EMA

test=develop

* Fix for step 0 & add unit test, test=develop

* fix grad clip， clip op belongs to Backward op when running in Parameter Server mode.

* add erf op and python interface.

* add fp16 support for erf op.

* add unitests for erf op and its python interface.

enhanced ops: conv2d, conv3d
elementwise_pow: change to a reasonable shape

* support elu activation double grad,test=develop

* delete the code commit in .cc,test=develop

* fix relu test unpass, test=develop

* add elu double grad kernel and unit test

* add caculate dX in elu double grad functor, test=develop

* update the commit code,test=develop

* add gelu plugin

* align trt bert with gpu

* add support for fused fc with relu,

* add unittest for bert trt

* add dygraph LayerList

* add unittest
test=develop

* add newline
test=develop

* typo fix
test=develop

* fix dim=[] bug in reduce ops