added ProgrammingError, cleaned API of abstract node by separating takeChild(...) from deleteChild(AbstractNodeSP)
changed paradigm from createChild<T>(...) to createNode<T>(ID) and appendChild(...) to be more flexible and have to write less code
ctor cleanup.
added a template method to ModelScene to manage node lists.
hide ID
cleaned up ctor
introduced class EditorContentPanel
type name cleanup
fixed bug in ValueNode::serialize(...): pointer to parent was not serialized.
cleaned up node creation and editing by introducing template methods to create editing dialogs.
renamed template type parameter to match real meaning.
startet to work on DatabaseRole and clean up editor infrastructure.
big cleanup
added gui to manage database roles
can manage tables
added support for database sequences
can manage database languages
can manage tablespaces
added aggregates
added database casts and database collations
added database encoding conversions