added ProjectChangeWatcher for projects

src/Main/Base/Project/Src/Project/AbstractProject.cs

@@ -53,7 +53,7 @@ namespace ICSharpCode.SharpDevelop.Project
 		public virtual void Dispose()
 		{
 			WorkbenchSingleton.AssertMainThread();
-			
+			watcher.Dispose();
 			isDisposed = true;
 			if (Disposed != null) {
 				Disposed(this, EventArgs.Empty);
@@ -116,6 +116,7 @@ namespace ICSharpCode.SharpDevelop.Project
 		#region Filename / Directory
 		volatile string fileName;
 		string cachedDirectoryName;
+		protected ProjectChangeWatcher watcher;
 		
 		/// <summary>
 		/// Gets the name of the project file.
@@ -134,6 +135,15 @@ namespace ICSharpCode.SharpDevelop.Project
 				WorkbenchSingleton.AssertMainThread();
 				Debug.Assert(FileUtility.IsUrl(value) || Path.IsPathRooted(value));
 				
+				if (watcher == null) {
+					watcher = new ProjectChangeWatcher(value);
+					watcher.Enable();
+				} else {
+					watcher.Disable();
+					watcher.Rename(value);
+					watcher.Enable();
+				}
+				
 				lock (SyncRoot) { // locking still required for Directory
 					fileName = value;
 					cachedDirectoryName = null;

src/Main/Base/Project/Src/Project/MSBuildBasedProject.cs

@@ -1246,6 +1246,8 @@ namespace ICSharpCode.SharpDevelop.Project
 		#region Saving
 		public override void Save(string fileName)
 		{
+			watcher.Disable();
+			watcher.Rename(fileName);
 			lock (SyncRoot) {
 				// we need the global lock - if the file is being renamed,
 				// MSBuild will update the global project collection
@@ -1258,6 +1260,7 @@ namespace ICSharpCode.SharpDevelop.Project
 					}
 				}
 			}
+			watcher.Enable();
 			FileUtility.RaiseFileSaved(new FileNameEventArgs(fileName));
 		}
 		#endregion

src/Main/Base/Project/Src/Project/ProjectChangeWatcher.cs

@@ -86,7 +86,7 @@ namespace ICSharpCode.SharpDevelop.Project
 			}
 		}
 
-		bool wasChangedExternally;
+		static bool wasChangedExternally;
 
 		void OnFileChangedEvent(object sender, FileSystemEventArgs e)
 		{