Extendsrelational tableswith a mutation and subscriber interface.

1. public interface Database extends Table
   1. public Line add(List<?> values)
   2. public Line add(Line line)
   3. public void remove(Line line)
   4. public void subscribe_change(Change_listener change_listener)

1. 21
1. Gel's Relational Database Change Listener
2. Gel's Relational Allocation Database
3. Gel's Relational Database