Fix up the NumPy warnings hack by using the actual "import_array()" function declaration instead of a wrong one.

Closes https://github.com/cython/cython/issues/3594

Closes https://github.com/cython/cython/issues/1462

Move the work directory of the examples tests into an 'examples/' subdirectory to get it out of the way of the other test types.

Make sure the module init function is declared as 'extern "C"' in C++ also when the CYTHON_NO_PYINIT_EXPORT option is used.
Closes #3414.

Closes #3038.

Fix optimisation of aligned '%' formats ('%05s', '%-5s') into the correct f-string alignment format.
Closes https://github.com/cython/cython/issues/3476

Floats do not support '{x:d}' formatting and need conversion to 'int' first.
Closes https://github.com/cython/cython/issues/3092

Improve error handling in "cython.array" creation code to avoid calling Py_BuildValue() with an exception set if "__pyx_format_from_typeinfo()" failed.

See https://github.com/cython/cython/pull/3562

See #1407.

These are mutable and therefore affect the stdlib build_ext options.

Fixes #2209

This was previously broken by the introduction of the "__PYX_ERR()" macro.

* Changed always_allow_keywords_T295 for Py3.9

https://bugs.python.org/issue37645 appears to change some error
messages slightly (including the qualname and not just the
function name). This change just allows doctest to cope with
both the new and old messages