Use cpack to create osx's dmg

Additionally, ensure proper installation of sounds and zonebg resources.
This by now is needed in order to create a working OSX package, but can be a base to create linux packages (deb/rpm) or a nsis script for windows in the future.
This causes MSVC build issue's when making the cockatrice executable.  Change line 103 to the following and it seemed to fix  it:

#ifdef Q_OS_MAC
        translationPath = QLibraryInfo::location(QLibraryInfo::TranslationsPath);
#endif
#ifdef Q_OS_WIN
		translationPath = app.applicationDirPath() + "/translations";
#endif