initial wxAboutStuff committed

[ABX]

Vadim Zeitlin <vadim at ...> writes:
> examples of using it in samples/dialogs/dialogs.cpp

In line 1180 in the sample

  info.SetVersion(wxVERSION_NUM_DOT_STRING);

fails in unicode builds and _T() is not a solution because this definition is
already concatenation while unicode prefix applu only to first element of
concatenation.

ABX