Adding scrollsToTop property for ScrollableView, allowing to disable it so a ScrollView can control the status bar event

TiUIScrollableView.h

-(void)manageRotation;
-(UIScrollView*)scrollview;
-(void)setCurrentPage_:(id)page;
-(void)setScrollingEnabled_:(id)enabled;
-(void)refreshScrollView:(CGRect)visibleBounds readd:(BOOL)readd;
-(void)setScrollsToTop_:(id)value; // New property added
@end

TiUIScrollableView.m

-(void)setDisableBounce_:(id)value
{
	[[self scrollview] setBounces:![TiUtils boolValue:value]];
}

//Allows use of scrollsToTop property on a scrollable view.
//This is useful when you have multiple scrollable views in your parent view, you can then
//set which scrollable view will respond to tapping the status bar to scroll to top.
//http://developer.apple.com/library/ios/#documentation/uikit/reference/UIScrollView_Class/Reference/UIScrollView.html
-(void)setScrollsToTop_:(id)value
{
	[[self scrollview] setScrollsToTop:[TiUtils boolValue:value]];
}