some cleanup and ensure the package file is deleted after install

src/Umbraco.Web/Models/PackageInstallModel.cs

@@ -15,11 +15,6 @@ namespace Umbraco.Web.Models
         [DataMember(Name = "packageGuid")]
         public Guid PackageGuid { get; set; }
 
-        ////TODO: Do we need this?
-        //[DataMember(Name = "repositoryGuid")]
-        //public Guid RepositoryGuid { get; set; }
-
-
         [DataMember(Name = "zipFileName")]
         public string ZipFileName { get; set; }