Remove unnecessary mondrian.{ico,xpm} files from samples directory.

Standardize on using sample.rc and sample icon in all the samples, it was
confusing that some of them used it and other didn't, without any apparent
logic.

Remove the now unnecessary icon files, including the dialogs sample icon which
seemed to be corrupted (this closes #11146).

Also replace multiple OS/2 resource files with a single one in the sample
directory. The OS/2 projects/makefiles would need to be updated to use them.

Remove dialogs sample icon.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@64645 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/doxygen/overviews/bitmap.h

@@ -33,7 +33,7 @@ include the XPM inline as below, since it's C code, or you can load it at
 run-time.
 
 @code
-#include "mondrian.xpm"
+#include "sample.xpm"
 @endcode
 
 Sometimes you wish to use a .ico resource on Windows, and XPMs on other
@@ -44,16 +44,16 @@ A macro, wxICON(), is available which creates an icon using an XPM on the
 appropriate platform, or an icon resource on Windows:
 
 @code
-wxIcon icon(wxICON(mondrian));
+wxIcon icon(wxICON(sample));
 
 // The above line is equivalent to this:
 
 #if defined(__WXGTK__) || defined(__WXMOTIF__)
-    wxIcon icon(mondrian_xpm);
+    wxIcon icon(sample_xpm);
 #endif
 
 #if defined(__WXMSW__)
-    wxIcon icon("mondrian");
+    wxIcon icon("sample");
 #endif
 @endcode