* update roialign

* update tool for roialign

* fix ceil for roialign

* fix ios build

* fix

* fix

* make it compatibile with the old version

* fix ios build

* trigger CI

* fix test

* order

* build

* remove code

* merge roialign

* accelerate ROIAlign

* update note

* rename func

* roialign version

* trigger CI

* fix roialign

* use ref for pre-calc in roialign

* retrigger CI

* pre-alloc

* fix type conversion warning

* fix MSVC _CRT_SECURE_NO_DEPRECATE warning

* type conversion: missing one

* fix  MSVC _CRT_SECURE_NO_DEPRECATE warning and type warning

* reformat

* convert google::protobuf::int64 to size_t to avoid type impl between msvc and gcc gap

* remove C++11 auto

* tab -> space

* add folder property for a better looking in visual studio or other property supported IDEs

* fix condition for not found protobuf

* 1. capitalize to lowercase
2. rename visual folder 'test' to 'tests'

* Downgrade minimum cmake required to 2.8

In some embedded system, the cmake version is still 2.8.x. So use
SET instead of APPEND to adapt to more envir.

* Set cmake minimum required version to 2.8.12

* Adapt for cmake 2.8.12 using target_compile_options instead of feature

* Fix openmp compiling error on cmake 2.8.12

* constraint input value to [-127, +127]

* keep new line at the end

* 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

* add the armv7a conv3x3s1 implement without overflow,remove old codes

* fix the bug of conv3x3s2 packed int8

* new int8 implement,weight quant by perchanel,better accuracy~

* fix the bug of conv3x3s1 packed int8 neon

* add the naive c fp32 and int8 winograd F(2,3)

* add the neon intrinsic int8 winograd F(2,3)

* optimize the armv7a int8 winograd F(2,3) with neon assembly

* optimize the armv7a int8 winograd F(2,3) input transform with assembly.

* add the requantize layer and int8 relu implement.

* add graph optimize conv1x1s2 -> conv1x1s1,begin optimize int8 aarch64.

* fix int8 bugs

* add the c naive im2col with sgemm

* add aarch64 int8 winograd f23, conv3x3s2 naive implement

* add the int8 sgemm conv7x7s2 on x86/armv7a platform

* optimize the int8 sgemm by neon intrinsic and packed kernel

* optimize the int8 sgemm with packed data

* optimize the int8 sgemm with armv7a neon assembly

* add the int8 sgemm on arm64-v8a platform

* perpare to merge latest codes from master

* add the int8 param files

* In the Class Net,add the fuse_network method

* fix the caffe2ncnn  bug that "DepthwiseConvolution" loss group num param

* fix windows build error

* remove wrong commit

* add ShuffleChannel layer, only cpp, no arm yet

* add   assign

* add depthwise deconvolution.

* add depthwise deconvolution.

* fix some syntax error and uncessary modification