Introduced the MasterController as part of working on loading catalogue information.

Need a central piece to manage the catalogue data per database to prevent loading
this multiple times. MasterController is now also used to enable reopening the
connection manager from a query window after the connection manager has been closed.

pgnamespace.h

@@ -0,0 +1,17 @@
+#ifndef PGNAMESPACE_H
+#define PGNAMESPACE_H
+
+#include <QString>
+#include <pgsql/libpq-fe.h>
+
+class PgNamespace
+{
+public:
+	PgNamespace();
+
+	QString name;
+	Oid owner = InvalidOid;
+	QString acl;
+};
+
+#endif // PGNAMESPACE_H