BGE: Add chgid property to make its value accessible throughout user interface

BGE: Change Id support, allow modify & clear if format has ‘ChangeIds’

PROMS/Volian.Controls.Library/DisplayTabControl.cs

@@ -103,6 +103,12 @@ namespace Volian.Controls.Library
 			get { return _MyCopyStep; }
 			set { _MyCopyStep = value; }
 		}
+		private string _ChgId;
+		public string ChgId
+		{
+			get { return _ChgId; }
+			set { _ChgId = value; }
+		}
 		#endregion
 		#region Events
 		/// <summary>