Several improvements

- Project files for win32 platform & compiling error fix
- Compiling error fix for MacOS
- Uses rand instead of arc4random for multi-platform support & srand call to AppDelegate
- Possible bug fix for GHBoneSkin initialization code
- Loop enabled animation uses randomRepeatTime even randomReplay is disabled.. I think SpriteHelper 2.0 tool has this issue too
- Performance improvement for GHSprite by using SpriteFrameCache