Merge pull request 'B2026-021-some-symbols-not-being-displayed-correctly' (#726) from B2026-021-some-symbols-not-being-displayed-correctly into Development

good for testing phase

PROMS/ReferencedObjects/LibSource/ctlXMLEditLib/roRichTextBox.cs

@@ -32,7 +32,7 @@ namespace ctlXMLEditLib
 		public void InsertSymbol( int symbcode)
 		{
 			int position = this.SelectionStart;
-			string sym = string.Format(symbcode < 256 ? "\'{0:X2}" : @"\u{0}", symbcode);
+			string sym = symbcode < 256 ? ((char)symbcode).ToString() : string.Format(@"\u{0}", symbcode);
 			this.SelectedRtf = RtfPrefixForSymbols + sym + @"}";
 			Select(position, -1);
 			Select(position + 1, 0);