- 
- fixed: GUI layout
- fixed: don't wait for the end of the "stop" sound if it wasn't started
(is deactivated)
- added: translation update
- 
- fixed: IsPlaying(): report correct state
- fixed: GUI layout
- added: also install Qt plugins
- added: "lang" entry
- added: show the release version number in the installer
- fixed: correct relative path of additional libraries, which should be
copied during install process