Clarify some comments.

src/AddIns/Analysis/UnitTesting/Model/ITest.cs

@@ -22,7 +22,7 @@ namespace ICSharpCode.UnitTesting
 		
 		/// <summary>
 		/// Gets whether this test allows expanding the list of nested tests.
-		/// If possible, this property should return the same value as NestedTests.Count.
+		/// If possible, this property should return the same value as <c>NestedTests.Count &gt; 0</c>.
 		/// However, when doing so is expensive (e.g. due to lazy initialization), this
 		/// property may return true even if there are no nested tests.
 		/// </summary>

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

@@ -302,11 +302,6 @@ namespace ICSharpCode.SharpDevelop.Project
 			}
 		}
 		
-		/// <summary>
-		/// Gets the list of items in the project. This member is thread-safe.
-		/// The returned collection is guaranteed not to change - adding new items or removing existing items
-		/// will create a new collection.
-		/// </summary>
 		[Browsable(false)]
 		public virtual IMutableModelCollection<ProjectItem> Items {
 			get {

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

@@ -37,8 +37,8 @@ namespace ICSharpCode.SharpDevelop.Project
 		
 		/// <summary>
 		/// Gets the list of items in the project. This member is thread-safe.
-		/// The returned collection is guaranteed not to change - adding new items or removing existing items
-		/// will create a new collection.
+		/// The returned collection is thread-safe; any accesses will synchronize with the project's <see cref="SyncRoot"/>.
+		/// Enumerating the items collection will create a snapshot of the collection.
 		/// </summary>
 		IMutableModelCollection<ProjectItem> Items { get; }
 		

src/Main/Base/Test/Dom/CSharpModelTestBase.cs

@@ -15,7 +15,6 @@ using Rhino.Mocks;
 
 namespace ICSharpCode.SharpDevelop.Dom
 {
-	[TestFixture]
 	public class CSharpModelTestBase
 	{
 		protected IProject project;

src/Main/Core/Project/Src/Util/AbstractCommand.cs

@@ -8,6 +8,7 @@ namespace ICSharpCode.Core
 {
 	/// <summary>
 	/// For compatibility with SD 4.x.
+	/// New code should use SimpleCommand instead.
 	/// 
 	/// TODO: make obsolete
 	/// </summary>
@@ -36,6 +37,7 @@ namespace ICSharpCode.Core
 	
 	/// <summary>
 	/// For compatibility with SD 4.x.
+	/// New code should use SimpleCommand instead.
 	/// 
 	/// TODO: make obsolete
 	/// </summary>