* fix pyncnn build

* warn puttext
* split dict

* fix(examples): exit program if load_param, load_model failed for clear error messsage

* ignore .cache dir for clangd

* check non-zero instead of -1 for load functions

* Reduce yolov5 post time.

sigmoid(X)<1, 
IF：box_confidence<prob_threshold
THEN: confidence=box_confidence*sigmoid(class_score)<box_confidence<prob_threshold,
So there is no need to calculate class_score when box_confidence<prob_threshold，and the confidence of most anchors is lower than the prob_threshold.

Co-authored-by: UNeedCryDear <UNeedCryDear@users.noreply.github.com>

Co-authored-by: v-shux <v-shux@microsoft.com>

* chore(examples): add YOLOX to ncnn examples

* fix(example): make C++98 happy

* apply code-format changes

* fix(example): fix #287 in yolox

* fix(example): make C++98 happy again

* apply code-format changes

Co-authored-by: FateScript <FateScript@users.noreply.github.com>

* just a spell check

* some misspell

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

* fix cmake 3.5.1 config error

* fix ubuntu16.04 build error

* vulkan cmake export templete

* 1) vulkan cmake dependency export. 2) support opencv_world import. 3) add BUILD_WITH_STATIC_CRT option

* Threads dependency

* NCNN_BUILD_WITH_STATIC_CRT option

* we do not support cmake before version 3.15 for option NCNN_BUILD_WITH_STATIC_CRT