Dispose ProjectChangeWatcher when solution is disposed.

Fixed adding 'AnyCPU' platform to a single project using the configuration editor.

Save "GlobalSection(NestedProjects)" in the correct order - SharpDevelop was saving it in the opposite order of the "Project"-sections. This was the cause of the whole .sln-file getting rearranged on every change, making merging .sln changes difficult.
Note that fixed SharpDevelop version will rearrange the solution one last time if the "NestedProjects" global section specifies a different order than the "Project"-sections.

src/Main/Base/Project/Src/Gui/Dialogs/SolutionConfiguration/EditAvailableConfigurationsDialog.cs

@@ -220,7 +220,7 @@ namespace ICSharpCode.SharpDevelop.Gui
 						IProjectAllowChangeConfigurations pacc = project as IProjectAllowChangeConfigurations;
 						if (pacc != null) {
 							if (editPlatforms) {
-								pacc.AddProjectPlatform(newName, dlg.CopyFrom);
+								pacc.AddProjectPlatform(MSBuildInternals.FixPlatformNameForProject(newName), dlg.CopyFrom);
 							} else {
 								pacc.AddProjectConfiguration(newName, dlg.CopyFrom);
 							}

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

@@ -359,11 +359,14 @@ namespace ICSharpCode.SharpDevelop.Project
 					
 					SaveProjectSections(folder.Sections, projectSection);
 					
-					ISolutionFolder subFolder;
+					// Push the sub folders in reverse order so that we pop them
+					// in the correct order.
 					for (int i = folder.Folders.Count - 1; i >= 0; i--) {
-						//foreach (ISolutionFolder subFolder in folder.Folders) {
+						stack.Push(folder.Folders[i]);
-						subFolder = folder.Folders[i];
+					}
-						stack.Push(subFolder);
+					// But use normal order for printing the nested projects section
+					for (int i = 0; i < folder.Folders.Count; i++) {
+						ISolutionFolder subFolder = folder.Folders[i];
 						nestedProjectsSection.Append("\t\t");
 						nestedProjectsSection.Append(subFolder.IdGuid);
 						nestedProjectsSection.Append(" = ");
@@ -1191,6 +1194,7 @@ namespace ICSharpCode.SharpDevelop.Project
 		#region System.IDisposable interface implementation
 		public void Dispose()
 		{
+			changeWatcher.Dispose();
 			foreach (IProject project in Projects) {
 				project.Dispose();
 			}