Marco Arment has updated his popular Instapaper Pro application, adding basic iOS 4 support and renaming the application to simply “Instapaper,” dropping the “Pro” designation. Instapaper 2.2.4 continues to support all of the features of the previous “Instapaper Pro” version and adds support for Fast App Switching on iOS 4, swipe gestures for page-turning on iOS 4 and iPad devices with improved page turn performance…