deprecate wxTR_EXTENDED and remove it from the docs

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@44964 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/latex/wx/treectrl.tex

@@ -65,8 +65,6 @@ to be deselected.  This is the default.}
 \twocolitem{\windowstyle{wxTR\_MULTIPLE}}{Use this style
 to allow a range of items to be selected.
 If a second range is selected, the current range, if any, is deselected.}
-\twocolitem{\windowstyle{wxTR\_EXTENDED}}{Use this style
-to allow disjoint items to be selected.  (Only partially implemented; may not work in all cases.)}
 \twocolitem{\windowstyle{wxTR\_DEFAULT\_STYLE}}{The set of flags that are
 closest to the defaults for the native control for a particular toolkit.}
 \end{twocollist}