[ 1578529 ] better docs for reference-counted objects

This already includes the change for wxBitmap, which
  is not COW yet.


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@42094 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/latex/wx/cursor.tex

@@ -84,7 +84,7 @@ On MacOS if the cursor is larger than 16x16 it is resized and currently only sho
 
 \func{}{wxCursor}{\param{const wxCursor\&}{ cursor}}
 
-Copy constructor. This uses reference counting so is a cheap operation.
+Copy constructor, uses \helpref{reference counting}{trefcount}.
 
 \wxheading{Parameters}
 
@@ -244,8 +244,7 @@ Returns true if cursor data is present.
 
 \func{wxCursor\&}{operator $=$}{\param{const wxCursor\& }{cursor}}
 
-Assignment operator, using reference counting. Returns a reference
-to `this'.
+Assignment operator, using \helpref{reference counting}{trefcount}.
 
 \membersection{wxCursor::operator $==$}\label{wxcursorequals}