This will allow using this class in the library code too.

No real changes yet, this is a pure refactoring.

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Make GetInfo() return information for numbers by default in the Unix
version too instead of asserting, as this is more consistent with the
MSW and Mac versions and also seems more useful.

This provides a more convenient way of testing wxLANGUAGE_DEFAULT than
selecting it from the dialog shown on startup.

This commit is best viewed ignoring whitespace-only changes.

Show that file dialogs, spin and calendar controls also respect the
selected locale conventions.

This shows that C and UI (or OS) locales can be different.

This is slightly more verbose, but more clear and allows to separate the
translations-related part from locale-changing one.

Creating the controls directly on wxFrame is not recommended and looks
ugly under MSW due to the wrong background being used, so add an
intermediate panel.

Show that we can use the translations to the user language even without
changing the locale.

Restrict the choice to using the current system locale or not using it,
as setting any other language doesn't, and can't, work under macOS.

It makes more sense to skip loading the translations too, if the user
decided not to use the current locale.

This commit is best viewed ignoring whitespace-only changes.

Getting this dialog all the time is annoying when testing, so add
another command line option to set the locale unconditionally.

This commit is best viewed ignoring whitespace-only changes.

No real changes, just make it possible to use these constants without
including the entire wx/intl.h.

Note that the existing headers including wx/intl.h need to keep
including it, unfortunately, as not doing it any longer would break
compilation of any code including them which relies on _() or
wxGetTranslation() being defined after including e.g. wx/dc.h. This was,
of course, never guaranteed, but in practice it worked for a very long
time, so don't break it now.

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This is more convenient than having to open the "About" dialog to see
the details of the locale being used.

It also makes it unnecessary to store wxLocale reference in the frame
class, simplifying the sample code.

Use it in the sample to show what (little) it can do right now.

This code, added back in 420de41 (workaround for buggy setlocale()
under AIX (without this wxLocale didn't work at all), 2005-09-18), is
probably irrelevant anyhow because AIX 5.2 must not be used any more,
but also seems to have lost its purpose at some time during the
intervening years, as we don't use "retloc" as argument to setlocale()
anyhow, so it is doubly safe to simply remove it.

Using setlocale() is not the right way to do it there, try checking if
the locale is supported by Core Foundation instead of whether it's
supported by the Unix layer which is neglected and not used under Mac.

No real changes, just allow wxUILocale code to use this struct without
including the full wx/intl.h.

This commit is best viewed with --color-moved git option.

Most of the code in this function was Unix-specific and didn't make
sense for Mac, where we never have to apply the workarounds in it nor
deal with languages specified without the territory etc, so separate Mac
branch using CoreFouundation API from the rest of the Unix code to make
things more understandable.

No real changes.

This is tidier than using #ifdefs in the same common file and also
ensures that initializing wxLocale affects wxUILocale too, which will be
important for compatibility when the code elsewhere is modified to use
wxUILocale::GetInfo() instead of wxLocale::GetInfo() in the upcoming
commits.

This commit is best viewed with --color-moved git option.

Always use the UI locale conventions for floating point numbers in
wxNumberFormatter, making it different from wxString::{To,From}Double()
functions that use C locale, which may, or not, correspond to the UI
locale.

This ensures that we use the decimal separator corresponding to the UI
locale of the application, rather than C locale, so that e.g. comma is
used under macOS even if setlocale() is not used.

The existing ToString() is not flexible enough to be used in wxGrid,
which supports specifying the width (and not just the precision) as well
as using formats other than "%g" and "%f" which are the only ones
supported by the existing function.

Note that currently the implementation simply calls wxString::Format()
and then adjusts the decimal separator, but it could, in principle, use
wxUILocale methods for formatting the floating point numbers using
native platform functions for doing this, e.g. CFNumberFormatter under
macOS.

This ensures that the correct, i.e. matching the users default, decimal
point separator is used even if setlocale() is not called.

Also simplify the code a bit by removing checks for wxUSE_INTL already
present in wxNumberFormatter itself.

Retrieve thr date format to use, even when wxUSE_INTL==0.

This is similar to the previous commit and ensures that the correct date
format is used even if setlocale() is not called.

Show that the numbers and dates in wxGrid use the expected formats.

Use the appropriate format for the dates by using the UI, rather than C,
locale, similarly to wxGrid.

Use a number > 1000 to show the difference between the locales.