Update CCSpriteBatchNode.cpp

Setting opacity of a sprite (via setOpacity or FadeOut/In action) has the sprite turning black, it should simply be opaque.  

Cause is in bool SpriteBatchNode::initWithTexture, third line, "if(tex->hasPremultipliedAlpha())" 
Fix is making it "!if(!tex->hasPremultipliedAlpha())"