This version of Casanova is worlds apart from the one which ran on UK TV some twenty plus years ago. Now, in 2005, Russell T Davies (in demand at the moment as the key writer of the new Doctor Who) has developed a Casanova for our times, with modern phrases and references (there are National Lottery slogans; Casanova sings the wheels on the carriage to his young son), while still devoting attention to the serious aspects of the story.David Tennant plays the young Casanova, swaggering his way from the Italia…