Added the Service namespace

Dalapi continues to generate the traditional 'non-testable' version of
the DAL exactly as before. There is an additional namespace 'Service'
that provides an ITableNameService interface and an TableNameService
class that implements the interface. The service class requires
instantiation with a connection string name, so it can run multiple
databases / schemas, and the interface can be used for TDD. This is a
more robust solution than the original DAL classes, even though they
both do the exact same thing.