add rich text tooltips for IVariable and IParameter

src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/XmlDoc/XmlDocTooltipProvider.cs

@@ -46,8 +46,7 @@ namespace ICSharpCode.AvalonEdit.AddIn.XmlDoc
 			} else if (mrr != null) {
 				e.SetToolTip(CreateTooltip(mrr.Member));
 			} else if (lrr != null) {
-				var ambience = AmbienceService.GetCurrentAmbience();
+				e.SetToolTip(new FlowDocumentTooltip(XmlDocFormatter.CreateTooltip(lrr.Variable)));
-				e.SetToolTip(ambience.ConvertSymbol(lrr.Variable));
 			}
 		}
 		

src/Libraries/NRefactory/ICSharpCode.NRefactory.CSharp/OutputVisitor/CSharpAmbience.cs

@@ -96,6 +96,12 @@ namespace ICSharpCode.NRefactory.CSharp
 				} else if (node is NamespaceDeclaration) {
 					writer.WriteKeyword(Roles.NamespaceKeyword, "namespace");
 					writer.Space();
+				} else  if (symbol is IParameter) {
+					writer.WriteKeyword(Roles.NamespaceKeyword, "parameter");
+					writer.Space();
+				} else if (symbol is IVariable) {
+					writer.WriteKeyword(Roles.NamespaceKeyword, "local variable");
+					writer.Space();
 				}
 			}
 			

src/Main/Base/Project/Editor/XmlDocFormatter.cs

@@ -75,5 +75,17 @@ namespace ICSharpCode.SharpDevelop.Editor
 			}
 			return b.CreateFlowDocument();
 		}
+		
+		public static FlowDocument CreateTooltip(ISymbol symbol)
+		{
+			var ambience = AmbienceService.GetCurrentAmbience();
+			ambience.ConversionFlags = ConversionFlags.StandardConversionFlags | ConversionFlags.ShowDeclaringType;
+			string header = ambience.ConvertSymbol(symbol);
+			
+			ambience.ConversionFlags = ConversionFlags.ShowTypeParameterList;
+			DocumentationUIBuilder b = new DocumentationUIBuilder(ambience);
+			b.AddCodeBlock(header, keepLargeMargin: true);
+			return b.CreateFlowDocument();
+		}
 	}
 }