Fix LT-21934: fork task to stop parser so control returns to user

Src/LexText/ParserCore/ParseFiler.cs

@@ -77,6 +77,16 @@ public class ParseFiler
 
 		#region Properties
 
+		/// <summary>
+		/// Are we in the process of stopping the thread this is running in?
+		/// </summary>
+		public bool Stopping;
+
+		/// <summary>
+		/// Are we updating word forms?
+		/// </summary>
+		public bool UpdatingWordforms;
+
 		#endregion Properties
 
 		#region Construction and Disposal

Src/LexText/ParserCore/ParserScheduler.cs

@@ -12,6 +12,7 @@
 using SIL.LCModel;
 using SIL.ObjectModel;
 using XCore;
+using System.Threading;
 
 namespace SIL.FieldWorks.WordWorks.Parser
 {
@@ -196,6 +197,16 @@ public bool TryAWordDialogIsRunning
 		}
 
 		protected override void DisposeManagedResources()
+		{
+			// Dispose the managed resources in a separate thread
+			// so that the user gets control back right away.
+			System.Threading.Tasks.Task.Run(() =>
+			{
+				FinishDisposeManagedResources();
+			});
+		}
+
+		private void FinishDisposeManagedResources()
 		{
 			m_thread.Stop();
 			m_thread.Dispose();

Src/LexText/ParserUI/ParserUIStrings.resx

@@ -344,7 +344,4 @@
   <data name="ksEnterComment" xml:space="preserve">
     <value>Please enter a comment for the parser report</value>
   </data>
-  <data name="ksStoppingParser" xml:space="preserve">
-    <value>Stopping the Parser (may take up to a minute)</value>
-  </data>
 </root>

Src/LexText/ParserUI/TryAWordDlg.cs

@@ -369,7 +369,6 @@ protected override void OnClosed(EventArgs ea)
 			m_persistProvider.PersistWindowSettings(PersistProviderID, this);
 			if (m_parserListener.Connection != null)
 			{
-				this.Text = ParserUIStrings.ksStoppingParser;
 				m_parserListener.Connection.TryAWordDialogIsRunning = false;
 				m_parserListener.DisconnectFromParser();
 			}