fix #801 Wrong validation on the textinput widget

If a textinput widget, with directOnBlurValidation set to false, has an error state, focusing and bluring the field removed the error state, which is wrong as no changes occurred
fix #806 Add some missing z-index on the splitter handles
fixed issue backgroundPositionX and backgroundPositionY on FF
less.js integration in the AT CSS template mechanism
fix for animations on backgroundPosition(X|Y) on FF only