Support for a custom schema

It's common for new users of Spring Security to begin their experience by adapting the JDBC user, group, or role mapping to an existing schema. Even though a legacy database doesn't conform to the expected Spring Security schema, we can still configure JdbcDaoImpl to map to it.

We will now update Spring Security's JDBC support to use our existing CalendarUser database along with a new calendar_authorities table.

We can easily change the configuration of JdbcUserDetailsManager to utilize this schema and override Spring Security's expected table definitions and columns, which we're using for the JBCP calendar application.