Fix for special characters in Doxygen comments.

Escape "-" characters in the beginning of the paragraph as they are not
handled properly by Doxygen otherwise.

Escape the space after "i.e." to prevent the brief doc string from being
terminated by it.

Escape "--" which is translated to a dash by Doxygen otherwise.

Closes #15228.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74064 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/richtext/richtextctrl.h

@@ -1890,7 +1890,7 @@ public:
     virtual void PaintBackground(wxDC& dc);
 
     /**
-        Other user defined painting after everything else (i.e. all text) is painted.
+        Other user defined painting after everything else (i.e.\ all text) is painted.
 
         @since 2.9.1
     */