To understand quite how disgruntled the reviews of the latest Bridget Jones diaries have been, you have to recall quite what she meant to her readers first time round. It wasn’t just the way she seemed to sum up the female condition for unmarried women in their thirties — indeed, she put a name on it, the singleton — who were torn between theoretical commitment to feminism and a creeping dread of never settling down and dying alone and getting eaten by Alsatians.