Created IndexModel for displaying the indexes on a table. Constraints can now show the SQL to drop and create them.

The keyword list is now directly based of the official keyword list from postgresql.

pglab/ConstraintModel.h

@@ -18,7 +18,7 @@ public:
 		NameCol, ///
 		NsCol, ///
 		SupportingIndexCol,
-		DefinitionCol,
+//		DefinitionCol,
 		colCount };
 
 	explicit ConstraintModel(QObject *parent = nullptr);
@@ -35,6 +35,7 @@ public:
 
 	//QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const override;
 
+	const PgConstraint& constraint(int row);
 protected:
 
 	virtual Oid getType(int column) const override;