* OP clip, merge_lod_tensor, convert/elementwise error message enhancement. test=develop

* add elementwise pool2d, prelu, shuffle channel
test=develop

* add scale and refine concat eltwise conveter
test=develop

* refine elementwise converter
test=develop

* refine ut test and enforce error.
test=develop

* modify const cast
test=develop

* change the ci trt from version 5. to 6.0

* paddle-trt dynamic shape support init

* conv+bias or conv+bn dynamic shape support
test=develop

* modity trt engine opconvert
test=develop

* fix ci error
test=develop

* refine trt int8 for dynamic range set
test=develop

* refine trt int8
test=develop

* paddle::framework::vectorize() templatization

test=develop

* update pybind/imperative.cc

test=develop

* revert update on unsqueeze_op.cc and warpctc_cudnn_op.cu.cc

test=develop

* fluid int8 train and trt int8 predict align.
trt int8 predict init
op converter

* 2. align fluid int8 train and trt int8 inference.
enhance quant dequant fuse pass
enhance op converter, trt engine, trt engine op, trt subgraph pass.

* 3. add delete_quant_dequant_pass for trt

test=develop

* 4. add the missing file
test=develop

* 5. i modify the c++ interface, but forget to modify the pybind code
fix the IS_TRT_VERSION_GE bug, and fix elementwise op converter
test=develop

1). add static trt load model
2). fix bug: when device_id is not 0, the trt will have a bug
test=develop

1). add static trt load model
2). fix bug: when device_id is not 0, the trt will have a bug
test=develop

* Initialize the elementwise plugin.

* Implement the basic CUDA kernel of elementwise plugin.
test=develop