Fixed SiteMapXmlReservedAttributeNameProvider so it will exclude "known" attributes from being added to the Attributes collection. This was causing each SiteMapNode to take up about double the amount of memory that it should have and will significantly improve scalability of the SiteMap.
Added validation for Controller and Area fields to ensure invalid characters are not supplied in the configuration.
Merge branch 'dev' of https://github.com/maartenba/MvcSiteMapProvider into dev