Add folder support to presentations plugin
Original Launchpad bug 1730475: https://bugs.launchpad.net/openlp/+bug/1730475
Reported by: raoul-snyman (Raoul Snyman).
Add folders like we have in the images plugin
Original Launchpad bug 1730475: https://bugs.launchpad.net/openlp/+bug/1730475
Reported by: raoul-snyman (Raoul Snyman).
Add folders like we have in the images plugin