Updated Documentation (HoughCircles)

Rewrite the note on HoughCircles documentation to make it more clear

Add note to clarify that the output vector of found circles is sorted by
descending order of centres accumulator values.

Also delete reductant lines on the HoughCircles documentation.

Added comments to hough circles function.

Added comments to icvhoughgradient

Misalignment in line 1183 corrected
samples: gpu: fix include of TickMeter
Fix determining bounding box of the edge collection in FillEdgeCollection().

There is necessary to account also x-coordinate of the end of the edge when determining bounding box of the edge collection.
Simplify overengineered code
Merge pull request #3470 from Dmitry-Me:simplifyOverengineeredCode
Merge pull request #3469 from a-wi:Fill_ellipse_arc_v3
Merge pull request #3463 from Dikay900:fix_sample_video_writer
Merge pull request #3453 from mshabunin:doxygen-others
Merge pull request #3443 from HelenWong:bug3363Fix
Prevent division by zero
White space and spelling in meanshift tutorial

Removed a leading whitespace from a parenthetical comment and corrected the spelling of "maybe"
Fixed typo in description of Rect operations
Python test: added options to provide local data path
Remove unnecessary kercn limitation of 4.

When accessing global memory by DWORD4, memory bandwidth
can be fully utilized on Intel platform. This patch will
make more image format(e.g. 8UC4) be processed in DWORD4
by work-item. After applying this patch, 3 subcase of
./opencv_perf_core --gtest_filter=OCL_RepeatFixture_Repeat.Repeat/*
can be speedup on HD4000 graphics card with Beignet:
OCL_RepeatFixture_Repeat.Repeat/2, 64% improvement.
OCL_RepeatFixture_Repeat.Repeat/6, 50% improvement.
OCL_RepeatFixture_Repeat.Repeat/8, 56% improvement.

Signed-off-by: Chuanbo Weng <chuanbo.weng@intel.com>
Remove unnecesary operations and calculations in loop body.

Signed-off-by: Yan Wang <yan.wang@linux.intel.com>
Use sincos instead of sin and cos.

Signed-off-by: Yan Wang <yan.wang@linux.intel.com>
It turns opengl gheck is not needed for win ctrl+s
Make Ctrl+S open save dialog on Gtk backend
Merge pull request #3482 from wangyan42164:ocl_brute_match_improve
Merge pull request #3483 from wangyan42164:ocl_orb_improve