* 1. for cross platform, use cv::CommandLineParser instead of getopt.h
2. use cv::glob to search folder instead of dirent.h
3. fix some other warnings of function from cstdlib
4. add some const and some auto

* 1. fix some other warnings of function from cstdlib
2. add some const and some auto
3. i forgot...

* switch quantize tools default on

* check OpenCV first, if not found, disable quantize tools

* add _CRT_SECURE_NO_DEPRECATE for msvc and remove *_s functions

* add _CRT_SECURE_NO_DEPRECATE for msvc and remove *_s functions

* keep the one line style block

* folding bracket

* dynamic_cast -> static_cast

* skip compile caffe tools

* add convolution_int8 requant test

* fix

* test int8requant

* revert code

* clean code

* fix CI error

* resolve review advices

* Update convolution_arm.cpp

Co-authored-by: nihui <shuizhuyuanluo@126.com>

baseclass Pipeline use virtual destruction

* add AbsVal layer test

* add 2d and 1d data test for AbsVal layer

* sort by alphabet

* 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'

* fix chgemm result dismatch

* fix misuse ldc as n

* fix gemm finished

* test conv_gemm_int8 and conv1x1_int8 passed

* format code