Made the re/undo code from the branch work in this, this is a manual copy as something went horribly wrong with the repository. Before building I first want to check if everything is there.[skip ci]

GreenshotPlugin/Interfaces/Drawing/IField.cs

@@ -0,0 +1,84 @@
+/*
+ * Greenshot - a free and open source screenshot tool
+ * Copyright (C) 2007-2015 Thomas Braun, Jens Klingen, Robin Krom
+ * 
+ * For more information see: http://getgreenshot.org/
+ * The Greenshot project is hosted on GitHub https://github.com/greenshot/greenshot
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 1 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+using System;
+using System.ComponentModel;
+
+namespace GreenshotPlugin.Interfaces.Drawing
+{
+	[Flags]
+	public enum FieldFlag
+	{
+		NONE = 0,
+		CONFIRMABLE = 1
+	}
+	public interface IFieldType
+	{
+		string Name
+		{
+			get;
+			set;
+		}
+	}
+
+	public interface IField : INotifyPropertyChanged
+	{
+		object Value
+		{
+			get;
+			set;
+		}
+		IFieldType FieldType
+		{
+			get;
+			set;
+		}
+		string Scope
+		{
+			get;
+			set;
+		}
+		bool HasValue
+		{
+			get;
+		}
+	}
+	/// <summary>
+	/// EventHandler to be used when a field value changes
+	/// </summary>
+	public delegate void FieldChangedEventHandler(object sender, FieldChangedEventArgs e);
+
+	/// <summary>
+	/// EventArgs to be used with FieldChangedEventHandler
+	/// </summary>
+	public class FieldChangedEventArgs : EventArgs
+	{
+		public IField Field
+		{
+			get;
+			private set;
+		}
+		public FieldChangedEventArgs(IField field)
+		{
+			Field = field;
+		}
+	}
+}