wxColour into a new wxXVisualInfo structure, and moved code
to initialize it to a new src/x11/utilsx.cpp file (utility
functions shared by wxMotif and wxX11).
Added (currently unused) code in wxMotif to
retrieve wxXVisualInfo; it will be used when wxMotif
is switched to bitmap.cpp from wxX11.
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@20056 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775