orm: Add bitwise op. support to SqlExpression
orm: SqlAggregate

Fix misspelled class and add expression support to SqlAggregate
orm: bug fixes
orm: Add support for DISTINCT to SqlAggregate
orm: Convert SLA to ORM
orm: Convert Team to ORM
orm: Convert Topic to ORM
orm: Convert Email to ORM
orm: Improve Dept's use of ORM

The commit also renames some fields in department table.
Role-based Access

Introduce the concept of role-based access for agents.
Implement role-based access
orm: Convert agents listing to be ORM based
Rename getRole to getUserType
roles : Implement role-based access system-wide