Alex Salmond’s ”Yes Scotland” campaign in the independence referendum, which is due to be launched in Edinburgh today, has been hit by a major blow as YouGov opinion poll shows most voters are unimpressed by his party’s core policy on separation of Scotland from Britain. Salmond will today embark on what he illustrated as “the biggest gamble of his political career” in the hope of winning hearts and minds by 2014. However, an opinion poll commissioned by Alistair Darling, the…