DAO refactoring - Use Spring NamedParameterJdbcTemplate instead of simple preparedStatement in DAO code

For the implementation of NAS-2212, I had to modify several DAO classes.

Right now all DAO code uses plain ol' PreparedStatements and populating is done by using parameter indices. Bluntly put, it's a real pain in the neck to modify/extend such code...

I'd recommend switching to Spring's NamedParameterJdbcTemplate that basically wraps a PreparedStatement but allows to used named parameters to populate it, hence making DAO modifications a whole lot easier.

Its a few hours' work, and I believe a most useful refactoring to do.