Generates OnChange event.
procedure Change; override;
TCustomRichViewEdit.Change method was overridden to support data-aware features of TDBRichViewEdit.
In addition to the actions inherited from RichViewEdit, this method also informs the linked dataset that data were modified.
Change can be useful if you need to modify document using 
viewer-style methods, see the example: Using viewer-style methods in DBRichViewEdit.