Added continuation bullet style for supporting multiple paragraphs in a list item

The user can 'delete' the bullet to create a continuation paragraph


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@72096 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/richtext/richtextctrl.h

@@ -2144,6 +2144,17 @@ public:
 
 // Implementation
 
+    /**
+        Processes the back key.
+    */
+    virtual bool ProcessBackKey(wxKeyEvent& event, int flags);
+
+    /**
+        Given a character position at which there is a list style, find the range
+        encompassing the same list style by looking backwards and forwards.
+    */
+    virtual wxRichTextRange FindRangeForList(long pos, bool& isNumberedList);
+
     /**
         Sets up the caret for the given position and container, after a mouse click.
     */