It's 39 years since abortion was legalised in this country, yet these days it's rarely discussed without mention of 'shame', 'mental trauma' or 'viability'. With pro-lifers dominating the debate, and even leftwingers describing abortion as a 'necessary evil', women's hard-won rights could soon be under threat. In an introduction to an eight-page special, Zoe Williams asks: are we just going to roll over?