Merge 2.4 into master

PR #2968: cce2d99 8578f9c
Fixed bug which caused crash of GPU version of feature matcher in stitcher

The bug caused crash of GPU version of feature matcher in stitcher when
we use ORB features.

PR #3236: 5947519
Check sure that we're not already below required leaf false alarm rate before continuing to get negative samples.

PR #3190
fix blobdetector

PR #3562 (part): 82bd82e
TBB updated to 4.3u2. Fix for aarch64 support.

PR #3604 (part): 091c7a3
OpenGL interop sample reworked not ot use cvconfig.h

PR #3792: afdf319
Add -L for CUDA libs path to pkg-config

Add all dirs from CUDA_LIBS_PATH as -L linker options to
OPENCV_LINKER_LIBS. These will end up in opencv.pc.

PR #3893: 122b9f8
Turn ocv_convert_to_lib_name into a function

PR #5490: ec5244a
fixed memory leak in findHomography tests

PR #5491: 0d5b739
delete video readers

PR #5574

PR #5202

modules/videoio/test/test_ffmpeg.cpp

@@ -431,6 +431,10 @@ TEST(Videoio_Video_parallel_writers_and_readers, accuracy)
         if (code == 1)
             std::cerr << "Couldn't delete " << *i << std::endl;
     }
+
+    // delete the readers
+    for (std::vector<VideoCapture *>::iterator i = readers.begin(), end = readers.end(); i != end; ++i)
+        delete *i;
 }
 
 #endif