Add a timeout event.wait_for() method.
Add a timeout event.wait_for() method.

Not exactly like std::condition_variable, but similar.

hrydgard/native,zhykzhykzhyk/ppsspp-native,libretro/ppsspp-native,Ced2911/native,Ced2911/native,unknownbrackets/native,zhykzhykzhyk/ppsspp-native,zhykzhykzhyk/ppsspp-native,Ced2911/native,libretro/ppsspp-native,hrydgard/native,libretro/ppsspp-native,unknownbrackets/native,hrydgard/native,unknownbrackets/native,libretro/ppsspp-native,unknownbrackets/native,hrydgard/native,zhykzhykzhyk/ppsspp-native