osx: clean up includes, we do not need cocoa what we *do* need is the very basics that animia already depends on anyway. these are basically guaranteed to be on any macos system, making it fairly portable now... I haven't tested this :) I don't have a macos machine right now...

#ifndef __sys__osx__dark_theme_h
#define __sys__osx__dark_theme_h

namespace osx {

bool DarkThemeAvailable();
bool IsInDarkTheme();
void SetToDarkTheme();
void SetToLightTheme();
void SetToAutoTheme();

} // namespace osx

#endif // __sys__osx__dark_theme_h