* [LITE][BM] add fill_const assign_value ops, test=develop

* * support download bm_sdk, test=develop

* [LITE][BM] add slice op

* [LITE][BM] fix concat issue

* [LITE][BM] support reduce full ops, test=develop

* [LITE][BM] change test_resnet50 to change test_classify

* [LITE][BM] add cast op

* [LITE][BM] add reduce and other ops, test=develop

* [LITE][BM] add reduce,cast and other ops, test=develop

* [LITE][BM] support VGG,Inception,Mobilenet,Darknet, test=develop

* Support bitman backend

* paddle lite cuda init
can run model with leaky_relu

* add the missing file.
test=develop

* add the load from memory interface.
test=develop

* refine this pr. fix comments
fix ci error
test=develop

* conv impl
fp32:
conv, conv+bais, conv+bias+relu, conv+bias+leaky_relu

int8:
conv, conv+bais+relu(int8 or fp32 output), conv+bias+leaky_relu(int8 or fp32 output)

can run conv+ bias+relu using cxx_api
test=develop

* move the lite/cuda/math to backends/cuda/math
test=develop