Fix filter and exception on duplicates

1) Minimize required method filter
2) Exception on duplicates generated by NUnit TestCaseAttribute

src/AddIns/Analysis/CodeCoverage/Project/Src/CodeCoverageClassTreeNode.cs

@@ -51,7 +51,8 @@ namespace ICSharpCode.CodeCoverage
 			// Add methods.
 			CodeCoveragePropertyCollection properties = new CodeCoveragePropertyCollection();
 			foreach (CodeCoverageMethod method in Methods) {
-				if ( !method.Name.Contains("<") && !method.Name.Contains("__") ) {
+				//if ( !method.Name.Contains("<") && !method.Name.Contains("__") ) {
+				if ( !method.Name.Contains("__") ) {
 					if (method.IsProperty) {
 						properties.Add(method);
 					} else {

src/AddIns/Analysis/CodeCoverage/Project/Src/CodeCoverageResults.cs

@@ -64,7 +64,7 @@ namespace ICSharpCode.CodeCoverage
 				assembly.Elements("Classes").Elements("Class").Where(
 					c =>
 					!c.Element("FullName").Value.Contains("__") && 
-					!c.Element("FullName").Value.Contains("<") &&
+					//!c.Element("FullName").Value.Contains("<") &&
 					c.Attribute("skippedDueTo") == null).Select(
 						c => c.Element("FullName").Value).Distinct().OrderBy(name => name);
 			foreach (string className in classNames) {

src/AddIns/Analysis/UnitTesting/Src/TestClassCollection.cs

@@ -139,10 +139,14 @@ namespace ICSharpCode.UnitTesting
 					break;
 				case TestResultType.Failure:
 					SetTestResult(TestResultType.Failure);
-					failedTestClasses.Add(c.QualifiedName, c);
+					if (!failedTestClasses.ContainsKey(c.QualifiedName)){
+						failedTestClasses.Add(c.QualifiedName, c);
+					}
 					break;
 				case TestResultType.Success:
-					passedTestClasses.Add(c.QualifiedName, c);
+					if (!passedTestClasses.ContainsKey(c.QualifiedName)){
+						passedTestClasses.Add(c.QualifiedName, c);
+					}
 					if (passedTestClasses.Count == Count) {
 						SetTestResult(TestResultType.Success);
 					} else if (passedTestClasses.Count + ignoredTestClasses.Count == Count) {
@@ -150,7 +154,9 @@ namespace ICSharpCode.UnitTesting
 					}
 					break;
 				case TestResultType.Ignored:
-					ignoredTestClasses.Add(c.QualifiedName, c);
+					if (!ignoredTestClasses.ContainsKey(c.QualifiedName)){
+						ignoredTestClasses.Add(c.QualifiedName, c);
+					}
 					if (ignoredTestClasses.Count == Count ||
 					    ignoredTestClasses.Count + passedTestClasses.Count == Count) {
 						SetTestResult(TestResultType.Ignored);