UISlider, UIToolbar and UIButton

UISlider
added implementation of UISlider
added all style able properties with exception of:
- (void)setThumbImage:(UIImage *)image forState:(UIControlState)state;
- (void)setMinimumTrackImage:(UIImage *)image forState:(UIControlState)state;
- (void)setMaximumTrackImage:(UIImage *)image forState:(UIControlState)state;

UIToobar
added implementation of UIToobar

UIButton:
added disabled state for background image to UIButton renderer