* split precision profiler from performance profiler. test=develop

* add mean op, test=develop

* split forward and backward, test=develop

* Support bitman backend

* add cv image process

* fix arm liunx build error

* add LITE_WITH_CV defien to make cv, test=develop

* fix cv format, annd add describe in utils/cv

* delete some Meaningless comments, test=develop

* set LITE_WITH_CV=OFF in build.sh, test=develop

* delete cv_enum.h in utils/cv, push the contents in cv_ennum.h to paddle_image_preprocess.h, test=develop

* according to reviews to redefine paddle_image_preprocess.h, test=develop

* add detailed note of flipParam, test=develop

* fix format in paddle_image_preprocess.h, test=develop

* fix error when build x86. test=develop

* lite_with_X86 does not contain lite_with_cv

* Initial support for XPU
* Fix compiling errors of XPU
* Move XPU op kernel bridges from backends to kernels to fix deps order
* Change the namespace and directory of XPU bridges
* Add XPU SDK
* Fix header files and namespace of XPU SDK
* Add unit tests for relu and conv2d ops
* Restore the modification of paddle_api_test
* Supports simple model which contains only a relu layer
* Add compiling scripts for XPU
* Fix compiling errors of XPU
* Add comments for XPU LoadModel and BuildModel

* Fix timer of arm cpu profiler. test=develop

* Fix un-added op in cmake.test=develop

* fix cmake error

* fix cmake error, test=develop

* Fix pass sequence. test=develop

* replace option with lite_option. test=develop

* disable profile mode by default. test=develop

* Fix error option name. test=develop

* paddle lite cuda init
can run model with leaky_relu

* add the missing file.
test=develop

move cmake functions to lite.cmake