* add opencl valid api for device

* Update shell for make benchmark_bin

* [LITE] Set high perf mode as default in mobile_light deme; Fix Precision Profiler caused by X86 header; Enhance profiler for opencl. test=develop

* v2.6 supports mask_demo, test=develop

* add crop
* add crop ut. test=develop
* fix format,test=develop

*  Add shufflenetv2 in test_libs demo, test=develop

* fix cuda demo. test=develop

* update type error. test=develop

* add train_demo, test=develop

* Ehance mobilenetv1/v2, add std_dev computation. test=develop

* Ehance cxx mobile_light demo, add std_dev computation. test=develop

* [LITE][OPENCL] Change fp32 fc to fp16's. test=develop

* fix act in conv3x3opt opencl kernel. test=develop

* [LITE][CMAKE] fix cmake for opencl tiny_pubish compile. test=develop

- 增加cuda c++ demo.
- 考虑到检测模型尾部一般是multiclass_nms，该kernel为host，如果fetch kernel为cuda的话，则会在此处插入无用的io_copy(host->cuda)，由于该原因，注释掉fetch的cuda kernel. 默认使用host的fetch kernel. 此处暗中进行的行为：每次predictor run完，都会默认把数据从cuda拷贝到cpu

* improve conv_dw profile with rel relu6 leakyrelu, test=develop

* add depthwise, test=develop

* fix ci error, test=develop

* fix cv demo print, test=develop

* [LITE][OPENCL] Change fp32 fc to fp16's. test=develop

* fix act in conv3x3opt opencl kernel. test=develop

* [LITE][DEMO] fix input arg. test=develop

* fix shutdownlog for std::endl. test=develop

* [LITE][DEMO] Enhance mobile_light demo. test=develop

* fix print. test=develop

* fix clang v7 error
* change ut, test=develop
* fix conv ut, test=develop

* fix

* fix format. test=develop

* fix format, test=develop

* fix resize error

* fix format. test=develop

* fix format, test=develop

* fix format

* note log(4) << x_image. test=develop

* note x_image printf. test=develop

* fix leakyrelu and tanh compute error, test=develop

* delete extra file, test=develop

* reset act

* fix conflict and readme, test=develop

* fix ios run error, test=develop

update mask detection demo

* make full_publish to fix link bug in mask demo

Update mask demo docs, add model download from paddlehub

* [DEMO] add mask detection demo, test=develop

* [DEMO] fix ssd detection demo bug, test=develop