add powerful este.ui.userAgent, remove lame este.mobile.propagateDevices and este.userAgent

new pretty useful class for CSS styling based on actual browser,
device, engine and platform
add goog.dom.classlist into este.ui.Component requires
update este.dom.merge docs
add stylus-nib bower dependency

some demos need it
add demo for este.ui.userAgent
new awesome este.ui.Scrollbar, the most advanced custom Scrollbar ever