Detection and decoding of curved QR-codes

* temp changes for curved qrcodes

* added api for curved qr code decoding

* fixed prototypes

* refactored curved qr code decoding

* refactored curved qr code decoding 2nd part

* refactored curved qr code decoding 3rd part

* refactored curved qr code decoding 4th part

* added tests for curved qr code decoding

* refactored curved qr code decoding 5th part

Fixes two errors when building with the options WITH_CUDA=ON and BUILD_CUDA_STUBS=ON on a machine without CUDA.

In the cudaarithm module, make sure cuda_runtime.h only gets included when CUDA is installed.

In the stitching module, don't assume that cuda is present just because cudaarithm and cudawarping are present (as is the case when building with the above options).

[GSoC] OpenCV.js: WASM SIMD optimization 2.0

* gsoc_2020_simd Add perf test for filter2d

* add perf test for kernel scharr and kernel gaussianBlur

* add perf test for blur, medianBlur, erode, dilate

* fix the errors for the opencv PR robot

fix the trailing whitespace.

* add perf tests for kernel remap, warpAffine, warpPersepective, pyrDown

* fix a bug in  modules/js/perf/perf_imgproc/perf_remap.js

* add function smoothBorder in helpfun.js and remove replicated function in perf test of warpAffine and warpPrespective

* fix the trailing white space issues

* add OpenCV.js loader

* Implement the Loader with help of WebAssembly Feature Detection, remove trailing whitespaces

* modify the explantion for loader in js_setup.markdown and fix bug in loader.js

Update documentation to reflect INTER_LINEAR_EXACT being
unsupported in remap