3.9 alpha 17

-added: Play and Stop buttons in Open Dialog
-changed: PlaySlots: Filenames are being displayed bold
-removed: Option Dialog: options whether to load/save hotkeys to scheme files
-changed: Hotkeys, "Simultaneous Play" and "PlayLooped" states will now always be saved to scheme files
-added: Open Scheme Dialog: "Properties to Load" from Scheme File can now be selected using checkboxes
-added: Add filename to "Recent Schemes" menu when saving a Scheme
-added: Right-Click on Volume/Panning Slider causes the Slider to reset