CCLayer的子類，在CCLayer的基礎上增加了繪製顏色的功能。
CCLayerColor新增的屬性：
GLubyteopacity
ccColor3B color_
ccVerter2F squareVertices_[4]
ccColor4F squareColors_[4]
ccBlendFunc blendFunc_
-(id) initWithColor: (ccColor4B)color width: (GLfloat)w height: (GLfloat)h
-(id)initWithColor: (ccColor4B)color
-(void) setContentSize: (CGSize)size
-(void) changeWidth: (GLfloat)w height: (GLfloat)h
-(void) changeWidth: (GLfloat)w
-(void) changeHeight: (GLfloat)h
-(void) updateColor
-(void) setColor: (ccColor3B)color
-(void) setOpacity: (GLubyte)o