BufferPoolController has a non virtual protected destructor (which is legitimate)

However, Visual Studio sees this as a bug, if you enable more warnings, like below
```
add_compile_options(/W3)     # level 3 warnings
add_compile_options(/we4265) # warning about missing virtual destructors
```

This is a proposition in order to silence this warning.

See https://github.com/ivsgroup/boost_warnings_minimal_demo for a demo of the same problem
with boost/exception.hpp

version 3.3.0-rc

Fix error message fisheye CALIB_CHECK_COND

Fix wrong mat access in introduction_to_pca.cpp

Remove unnecessary Non-ASCII characters from source code (#9075)

* Remove unnecessary Non-ASCII characters from source code

Remove unnecessary Non-ASCII characters and replace them with ASCII
characters

* Remove dashes in the @param statement

Remove dashes and place single space in the @param statement to keep
coding style

* misc: more fixes for non-ASCII symbols

* misc: fix non-ASCII symbol in CMake file

how_to_scan_images.markdown: fix grammar mistakes

The old error message was not giving any hint which input array (image)
led to an ill conditioned matrix. This made it near impossible to
identify poor images in a larger set.

A better approach would be to implement a checker function which gives
each image a rating before the real calibration is performed. This could
also include some image properties like sharpness, etc.