add some features for  EJBindingAdBanner

adBanner.alwaysPortrait :   if true force the iAd to be Portrait mode,  or  iAd to be auto mode
adBanner.isAtRight:  if use "Portrait iAd" in Landscape device, let ad align to right

adBanner.x :  get/set Position X
adBanner.y :  get/set Position Y

adBanner.width (readOnly)   return the adBanner's real size ( banner.frame's size)
adBanner.height (readOnly)   return the adBanner's real size ( banner.frame's size)