* add is_test to pooling and activations

add prop_kind support for layers activation. conv and pooling

add a pass that sets is_test to true

add transpiler version of is_test pass

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* patch test and pass

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* add pass to analyzer.h

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* add is_test attr description & pass only on mkldnn

in:
activation_op.cc
batch_norm_op.cc
conv_op.cc
dropout_op.cc
lrn_op.cc
pool_op.cc
sequence_pool_op.cc
softmax_op.cc

* fix is_test handling for activation pool and conv

* change description of is_test for all layers again

* remove GetAttr(use_mkldnn) from pass

* rename correct_mkldnn_test_phase to is_test

and remove dependency on MKLDNN
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* review fix magic number

* two if(..)s into one

* Check is_test once and pass mkldnn forward prop kind

* dereference shared_ptr with * (without get())

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* add is_test_pass back

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* add selu

* use for range
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* add API
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* follow comment
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* update API.spec
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* Refine the tester for MixedRTPredictor.
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* Enable the profiler in TensorRT engine.

* Support the use of combined inference model in TensorRT unittest, and print the shape of feed targets.

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* human readable memory warns test=develop

* update test=develop

* refine test=develop

* fix build test=develop

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* Support softmax return in softmax_with_cross_entropy

* Add test for return_softmax=False

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Density prior box operator for image detection model.

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