* some ci tweaks

* workaround windows-2016 cache

For compatiblity for old compilers such as ndk-r16b.
`fabs()` keeps result stable.

ref: https://github.com/Tencent/ncnn/issues/2372

* update operators.md, add binaryop/Operation type

* fix with_scalar

* Update operators.md

* Update operators.md

* Add LSTM and softmax to operators.md

* Fix lowercase and support_inplace

* recognize apple M1

* macos ios cpuset and thread affinity

* big little cpu topology for macos and ios

* silence affinity not supported error

prvious -> previous

* codecov for arm32 aarch64, vs2017 ci

* vs2017 default to x86 even on x64 host

* Add readme for keras2ncnn

* Add supported model variants

* Fix supported model variants

* Add extract without convert pack/fp1632

* SSE2: BatchNorm

* Fixed batch norm in AVX configuration

* Optimized register size switch

* Attempt to pass CI

* Attempt to pass CI

* Bias op

* Element wise ops

* Support packing on x86 by default

* Fixed macro range in bias

* Use aligned read for packed data

* Update testutil.h

* Update pooling_x86.cpp

* Support wasn SIMD

* Fix emscripten compiler flags

* fix build

* more ci fix

* concat x86 pack4

* flatten x86 pack4

* more x86 pack4

* ci pass

* fix

* enable sse2 mathfun

* enable --experimental-wasm-simd
Co-authored-by: Nnihui <shuizhuyuanluo@126.com>
Co-authored-by: Nnihuini <nihuini@tencent.com>

* fix compiling failure on cxx14

* fix compile failure when NCNN_PIXEL off

* do not export pixel api when NCNN_PIXEL off

* disable squeezenet test when NCNN_PIXEL off

* do not build ncnn2table and examples when NCNN_PIXEL off

* make cmakedefine header independent

* restore platform.h.in
Co-authored-by: Nnihui <shuizhuyuanluo@126.com>
Co-authored-by: Nnihuini <nihuini@tencent.com>

Update README.md for Netron.app