* Fix warning C4244 in src/layer/normalize.cpp
C4244: '=': conversion from 'double' to 'float', possible loss of data
* Fix warning C4244 in src/layer/requantize.cpp
C4244: 'initializing': conversion from 'double' to 'int', possible loss of data
* Fix warning C4244 in src/mat_pixel_resize.cpp
C4244: '=': conversion from 'double' to 'int', possible loss of data
* Fix warning C4244 in src/mat_pixel.cpp
C4244: '=': conversion from 'int' to 'float', possible loss of data
* Fix warning C4267 in src/modelbin.cpp
C4267: 'initializing': conversion from 'size_t' to 'int', possible loss of data
* Fix warning C4244 in src/layer/batchnorm.cpp
C4244: 'initializing': conversion from 'double' to 'float',
possible loss of data
* Fix warning C4244 in src/layer/padding.cpp
C4244: 'argument': conversion from 'const float' to 'T', possible loss of data
* Fix warning C4244 in src/layer/priorbox.cpp
C4244: '=': conversion from 'double' to 'float',
possible loss of data
C4244: 'initializing': conversion from 'double' to 'float',
possible loss of data
* Change DataReader::read()'s signature to fix warning C4267
This CL fixes lots of warning "C4267: 'initializing': conversion from
'size_t' to 'int'" in our codebase by matching DataReader::read()'s
signature to fread().
* Fix warnings C4244 and C4267 in tools/ncnnoptimize.cpp
C4244: 'initializing': conversion from 'double' to 'float',
possible loss of data
C4267: 'initializing': conversion from 'size_t' to 'int',
possible loss of data
* Fix warning C4244 in src\layer\selu.cpp
C4244: '=': conversion from 'double' to 'float', possible loss of data
* Fix warning C4244 in src\layer\cast.cpp
C4244: '=': conversion from 'double' to 'float', possible loss of data
C4244: 'return': conversion from 'float' to 'signed char', possible loss of data
* Fix warning C4244 in src\layer\psroipooling.cpp
C4244: 'initializing': conversion from 'double' to 'float',
possible loss of data
C4244: 'initializing': conversion from 'double' to 'int',
possible loss of data
* CMake improvement
* Fix bugs
* Fix typo
* Propagate vulkan dependency
* import vulkan
* add config files, now exported target cmake should be able to find packages
* Propagate no-rtti and no-exception
* Provide a option to control rtti and exception in mobile platform
* Make cmake clean
* Resolve conflicts
* Update CMake
PIE is propagated by INTERFACE_POSITION_INDEPENDENT_CODE
* Remove bad things
nihui