Closes #308, performance improvements in SiteMapHierarchyBuilder for large numbers of SiteMap nodes.
Fixes #318, null types inadvertently returned from MvcSiteMapNodeAttributeDefinitionProvider.GetTypesFromAssembly() method.
Fixes #316, security trimming not functioning with AttributeRouting and MVC 5.1.x.
Fixes CSS for the menu so it is compatible with the default MVC5 template.
Added IEquality<ISiteMapNode> to the ISiteMapNode type, and override Equals, ==, !=, GetHashCode, and ToString on SiteMapNode, so the equality check uses the Key of the node if the memory location is different, as discussed in #310.
Merge branch 'patch-node-equality' into dev