Replaced notion of session uuid by session id which is more generic (could be a uuid, or something else).

Use STRING_TABLE for the implementation of session data container.
Added a few missing comments.

library/server/wsf/session/wsf_session.e

@@ -7,26 +7,43 @@ note
 deferred class
 	WSF_SESSION
 
-feature -- Access		
+feature -- Access
+
+	id: READABLE_STRING_8
+			-- Session identifier.
+		deferred
+		end
 
 	uuid: READABLE_STRING_8
+		obsolete
+			"Use `id' which is more general [2014-03]"
 		deferred
 		end
 
 	data: WSF_SESSION_DATA
+			-- Data associated with current session.
 		deferred
 		end
 
 	expiration: detachable DATE_TIME
+			-- Expiration date for current session, if any.
 		deferred
 		end
 
 	expired: BOOLEAN
+			-- Is current session expired now?
+		do
+			Result := expired_at (create {DATE_TIME}.make_now_utc)
+		end
+
+	expired_at (dt: DATE_TIME): BOOLEAN
+			-- Is current session expired at date and time `dt'?
 		do
 			if attached expiration as e then
-				Result := e < (create {DATE_TIME}.make_now_utc)
+				Result := e < (dt)
 			end
 		end
+
 feature -- status
 
 	is_pending: BOOLEAN
@@ -36,27 +53,32 @@ feature -- status
 		end
 
 	is_destroyed: BOOLEAN
+			-- Is current session in destroyed state?
 		deferred
 		end
 
 feature -- Entries
 
-	table: TABLE_ITERABLE [detachable ANY, READABLE_STRING_32]
+	table: TABLE_ITERABLE [detachable ANY, READABLE_STRING_GENERAL]
+			-- Table of session data indexed by key
 		do
 			Result := data
 		end
 
-	item (k: READABLE_STRING_GENERAL): detachable ANY
+	item alias "[]" (k: READABLE_STRING_GENERAL): detachable ANY assign remember
+			-- Session value associated with key `k'.
 		do
 			Result := data.item (table_key (k))
 		end
 
 	remember (v: detachable ANY; k: READABLE_STRING_GENERAL)
+			-- Remember value `v' in association with key `k'.
 		do
 			data.force (v, table_key (k))
 		end
 
 	forget (k: READABLE_STRING_GENERAL)
+			-- Forget about value associated with key `k'.
 		do
 			data.remove (table_key (k))
 		end
@@ -71,14 +93,16 @@ feature {NONE} -- Implementation
 feature -- Control
 
 	destroy
+			-- Destroy current session.
 		deferred
 		end
 
 	commit
+			-- Commit current session, including data associated.
 		deferred
 		end
 
-	apply_to (h: HTTP_HEADER_BUILDER; req: WSF_REQUEST; a_path: detachable READABLE_STRING_8)
+	apply_to (h: HTTP_HEADER_MODIFIER; req: WSF_REQUEST; a_path: detachable READABLE_STRING_8)
 			-- Apply current session to header `h' for request `req' and optional path `a_path'.
 			-- note: either use `apply_to' or `apply', not both.
 		deferred