TRichView + ExpressEditors integration.

version 1.5.8

Requires TRichView 16.6
Tested with: 
- DevExpress VCL v15.1.4 (v2015 vol 1.4) - Released on 27 Aug 2015
- DevExpress VCL v15.2.6 (v2015 vol 2.6) - Released on 12 May 2016

Installation: add the following files in any package:
cxTRichView.pas
cxDBTRichView.pas
cxTRichViewReg.pas
cxTRichViewRepositoryItems.pas
Install this package.

Two new components will be available: TcxTRichViewEdit and TcxDBRichViewEdit.
These controls contain TRichViewEdit as an inner editor,
Inner editor is accessible in InnerEditor property. It's already created with
RVStyle, so you do not need to create an external TRVStyle component.

Properties property has almost all TRichViewEdit's published properties and
events. Probably, some properties of TRVStyle should be added there too - on
request.

New properties of Properties:
- ScrollBars, replaces VScrollVisible and HScrollVisible;
- EditValueSaveFormat, with possible values:
 * cxrvvfAnsiText
 * cxrvvfUnicodeText,
 * cxrvvfRTF
 * cxrvvfRVF (default). 
 It specifies the format returned in cxTRichViewEdit.EditValue. 
 TcxDBTRichViewEdit, or TcxTRichViewEdit in a grid store this value in a database.
- VisibleLineCount; if set to positive value, defines height of the
control/grid cell; This height is calculated for one paragraph of the 0th 
style, having VisibleLineCount lines of text of the 0th style.
When used in a grid, if VisibleLineCount=0, the size of cell is calculated automatically
to display all the content
- DefFont - a default font for new documents; it is applied to TextStyles[0]; for text values, this is the text font;
- Unicode - a default value of Unicode property for all text styles.
DefFont and Unicode are applied before loading EditValue. 
Additionally, in TcxTRichViewEdit, if you change values of these properties, they are applied immediately if the document is empty.
If you want to apply them to non-empty document, reassign EditValue:
  cxTRichViewEdit1.Properties.DefFont.Name := 'Tahoma';
  cxTRichViewEdit1.EditValue := cxTRichViewEdit1.EditValue;

- OnLoadValue event occurs when EditValue property is assigned (after it is loaded
  in InnerEditor, but before calling InnerEditor.Format). InnerEditor is passed in
  the Sender parameter of this event.

Background color is controlled by DX styles, if you change
Properties.EditValueSaveFormat from cxrvvfRVF, or exclude rvfoSaveBack from
Properties.RVFOptions.
Color of text (more exactly, of the 0th text style) is controlled by DX
styles, if  Properties.EditValueSaveFormat is cxrvvfAnsiText or
cxrvvfUnicodeText.
