Add start of selection api, support for HasSelection, SelectAll and DeleteSelection along with documentation. Implement for IE and WebKitGTK and add stubs for OSX WebKit.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/SOC2011_WEBVIEW@68195 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/gtk/webview_webkit.h

@@ -138,6 +138,11 @@ public:
     virtual void SetEditable(bool enable = true);
     virtual bool IsEditable();
 
+    //Selection
+    virtual void DeleteSelection();
+    virtual bool HasSelection();
+    virtual void SelectAll();
+
     /** FIXME: hack to work around signals being received too early */
     bool m_ready;