Documentation of canonical signal/slot signatures missing/not easily accessible.

See parent task. The sections 'Overviews/Signals and Slots' lists

connect(signalMapper, SIGNAL(mapped(const QString &)), this, SLOT(readFile(const QString &)));

which should be:

connect(signalMapper, SIGNAL(mapped(QString)), this, SLOT(readFile(QString)));

Documentation about canonical signatures should be added wrt performance aspects.