MACOSX: Use bundle name for config and log file names

The idea here is that we can package a game in a custom bundle using
the scummvm executable, and use the game name as bundle name. It will
then use its own config and log files rather than share the ones from
the standalone ScummVM app.

backends/platform/sdl/macosx/macosx_wrapper.h

@@ -31,5 +31,6 @@ bool setTextInClipboardMacOSX(const Common::U32String &text);
 Common::String getDesktopPathMacOSX();
 Common::String getResourceAppBundlePathMacOSX();
 Common::String getAppSupportPathMacOSX();
+Common::String getMacBundleName();
 
 #endif