A bundle of improvements at webapp side

[FrankChen021]

1. enable graceful shutdown
2. Support to use 'alias' name in the list and group by query
3. fix http-outgoing dashboard by adding missed legend
4. support to close the detailed table and show interval for this table
5. allow directly expression in the client side query
6. use server-sort for data shown in a table that query data with LIMIT clause