Factor out the anchor prefix to easily allow switching to #!

client/lib/item.dart

Index: client/lib/item.dart
diff --git a/client/lib/item.dart b/client/lib/item.dart
index 15cdbd1c770698caf2f5dc83d0253ddc363ad152..c1dcaff9b8e75c65d91ce063569eb10c7afe998e 100644
--- a/client/lib/item.dart
+++ b/client/lib/item.dart
@@ -215,6 +215,9 @@ class Filter {
   /// Creates a link for the href attribute of an [AnchorElement].
   String get linkHref => qualifiedName;
 
+  /// [linkHref] but with the leading # separator.
+  String get prefixedLinkHref => locationPrefixed(linkHref);
+
   /// The [DocsLocation] for our URI.
   DocsLocation get location => new DocsLocation(qualifiedName);
 
@@ -237,6 +240,9 @@ class Filter {
 
   String get anchorHref => anchorHrefLocation.withAnchor;
 
+  /// [anchorHref] but with the leading # separator.
+  String get prefixedAnchorHref => locationPrefixed(anchorHref);
+
   bool get isLoaded => true;
 
   Item memberNamed(String name, {Function orElse : nothing}) => nothing();