Add user add/edit (#19)

- Add makeHash function to simplify code around DotLiquid hashes
- Add context extension to determine if a user has an access level
- Add someTask function to simply Task.FromResult (Some x)

src/MyWebLog/Caches.fs

@@ -50,6 +50,11 @@ module Extensions =
 
         /// The web log for the current request
         member this.WebLog = this.Items["webLog"] :?> WebLog
+        
+        /// Does the current user have the requested level of access?
+        member this.HasAccessLevel level =
+            defaultArg (this.UserAccessLevel |> Option.map (AccessLevel.hasAccess level)) false
+
 
 
 open System.Collections.Concurrent