I will do that. I will update my own Launcher due to a feature request, and then I will look into compiling your Launcher with Qt and performing necessary changes (if any). I will post back when I do this.
There will be for sure, cause the non-portable code is separated in arch by dirs. And OSX one is empty. I'll prepare some teplate for you (function declarations, project file, etc).
EDIT: Done, qmake project file "should" be ok. For the source look into src/macx dir. For an example of what to expect look into src/win, src/unix.
Functions you'd need to implement:
// returns dir where game executable and "data" dir exist (here's the problem as I dont know whether fs2 data is bundled in .app in OSX or not, never seen it in my life. if it is bundled then this will require some redesign
// returns config dir (f.e. ~/.fs2_open on linux)
// returns any writeable dir (flags.lch will be written to it)
// runs the command with parameters and eventually waits for the command to finish
bool System::run(const QString &exec, const QStringList ¶ms, bool waitForEnd)
// self explanatory
bool System::runBrowser(const QString &url)
// miliseconds sleep
int System::mSleep(int msec)
// i think you can leave the following as it is