generalize constraints to 'wa' for VSX registers

…c4.9

Just like with the other headers in the rest of the file.

See e.g. https://stackoverflow.com/questions/36831465/what-difference-does-it-make-when-i-include-limits-or-limits-h-in-my-c-cod
for the reasons, the most important one being that limits.h does not respect
namespaces, which can make problems for downstream consumers of cvdef.h.

* Fix bug 16410 and add test

* imgproc(connectedcomponents): avoid manual uninitialized allocations

* imgproc(connectedcomponents): force 'odd' chunk range size

* imgproc(connectedcomponents): reuse stripeFirstLabel{4/8}Connectivity

* imgproc(connectedcomponents): extend fix from PR14964

This is a correction of the previously missleading documentation and a warning related to a common calibration failure described in issue 15992

* corrected incorrect description of failed calibration state.

see issue 15992

* calib3d: apply suggestions from code review by catree

…torial-python

* Add python version of panorama_stitching_rotating_camera and perspective_correction

* Updated code

* added in the docs

* added python code in the docs

* docs change

* Add java tutorial as well

* Add toggle in documentation

* Added the link for Java code

* format code

* Refactored code