Reorged source tree.

src/NTwain/SourceEnableMode.cs

@@ -0,0 +1,21 @@
+namespace NTwain
+{
+	/// <summary>
+	/// Indicates how the source should be enabled in a TWAIN session.
+	/// </summary>
+	public enum SourceEnableMode
+	{
+		/// <summary>
+		/// Start acquiring without driver UI.
+		/// </summary>
+		NoUI,
+		/// <summary>
+		/// Start acquiring with driver UI.
+		/// </summary>
+		ShowUI,
+		/// <summary>
+		/// Show driver UI for settings change but no acquisition.
+		/// </summary>
+		ShowUIOnly
+	}
+}