Add wxRichMessageDialog class.

This is a generalization of wxMessageDialog based on the native task dialog
under recent (Vista and later) Windows versions and implemented generically
for the other ports for now.

It provides the possibility to use additional controls in the message boxes
(checkbox useful for the "Don't ask me again" kind of dialogs and collapsible
detailed explanations field) and better look and feel under Windows.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65349 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/chkconf.h

@@ -929,6 +929,14 @@
 #   endif
 #endif /* !defined(wxUSE_RIBBON) */
 
+#ifndef wxUSE_RICHMSGDLG
+#   ifdef wxABORT_ON_CONFIG_ERROR
+#       error "wxUSE_RICHMSGDLG must be defined, please read comment near the top of this file."
+#   else
+#       define wxUSE_RICHMSGDLG 0
+#   endif
+#endif /* !defined(wxUSE_RIBBON) */
+
 #ifndef wxUSE_SASH
 #   ifdef wxABORT_ON_CONFIG_ERROR
 #       error "wxUSE_SASH must be defined, please read comment near the top of this file."
@@ -1539,6 +1547,17 @@
 #   endif
 #endif /* wxUSE_REARRANGECTRL */
 
+#if wxUSE_RICHMSGDLG
+#    if !wxUSE_MSGDLG
+#        ifdef wxABORT_ON_CONFIG_ERROR
+#            error "wxUSE_RICHMSGDLG requires wxUSE_MSGDLG"
+#        else
+#            undef wxUSE_MSGDLG
+#            define wxUSE_MSGDLG 1
+#        endif
+#    endif
+#endif /* wxUSE_RICHMSGDLG */
+
 /* don't attempt to use native status bar on the platforms not having it */
 #ifndef wxUSE_NATIVE_STATUSBAR
 #   define wxUSE_NATIVE_STATUSBAR 0