Varaible names renamed. Macro definitions fixed. findEndContourPoint function fixed. findContoursInInterval adjusted.

Improves findContours using SSE _mm_movemask_epi8 to find next contour point. Cleaned up code a little bit

  * use universal intrinsic for accumulate series using float/double
  * accumulate, accumulateSquare, accumulateProduct and accumulateWeighted
  * add v_cvt_f64_high in both SSE/NEON
  * add test for conversion v_cvt_f64_high in test_intrin.cpp
  * improve some existing universal intrinsic by using new instructions in Aarch64
  * add workaround for Android build in intrin_neon.hpp

* Use `nth_element()` to find the median instead of `sort()` in `LMeDSPointSetRegistrator::run()`

* Improves performance of this part of LMedS from `n log(n)` to `n` by avoiding doing a full sort.

* Makes LMedS 2x faster for 100 points, 4x faster for 5,000 points in `EstimateAffine2D()`.

* LMedS is now never more than 2x slower than RANSAC and is faster in some cases.

* Added 2-channel ops to match existing 3-channel and 4-channel ops

* v_load_deinterleave() and v_store_interleave()

* Implements float32x4 only on SSE (but all types on NEON and CPP)

* Includes tests

* Will be used to vectorize 2D functions, such as estimateAffine2D()

 - also some minor changes to the respective sample cpp file

* expose 2 extra methods from ml::TrainData: getNames() and getVarSymbolFlags(). The first one returns text labels from CSV (if the data has been loaded from CSV); the second one returns a matrix of boolean values; its n-th element is 1 iff the corresponding column in the CSV uses symbolic names, not numbers.

* check that the dynamic_cast succeeds

* Add Grana's connected components algorithm for 8-way connectivity. That algorithm is faster than Wu's one (currently implemented in opencv). For more details see https://github.com/prittt/YACCLAB.

* New functions signature and distance transform compatibility

* Add tests to imgproc/test/test_connectedcomponents.cpp

* Change of test_connectedcomponents.cpp for c++98 support

Also put "object" targets to off by default (they doesn't work well)

strong and retain are synonymous but using strong along with  obsolete synonym retain in one file is negligent

Returning to Win2k value is possible via this CMake option:

    cmake -DOPENCV_EXTRA_FLAGS="/D_WIN32_WINNT=0x0500" ...