EPiServer 7.5 - EPiServer.UI.Admin.SiteMgmt Missing

In EPiServer 7.5, the namespace EPiServer.UI.Admin.SiteMgmt has been removed and site & host management now being implemented with SiteDefinitionRepository and SiteDefinition.Current. 

Example Code:

In EPiServer < 7.1

Get sites

 var sites = SiteInformationHandler.GetSitesInformation(true);  

Get Host:

 var hosts = SiteInformationHandler.GetSiteInformation(this.SiteID, true);  

In EPiServer > 7.5

Get sites

 var siteDefinitionRepository = ServiceLocator.Current.GetInstance<SiteDefinitionRepository>();  
 var sites = siteDefinitionRepository.List().ToList();  

Get Host:

 var hosts = SiteDefinition.Current;