LONDON (Reuters) - Bank of England Governor Andrew Bailey said on Monday that the central bank should start to reverse its quantitative easing asset purchases before raising interest rates on a sustained basis, a reversal of long-standing BoE policy.The BoE increased its bond purchase target to £745 billion last week, and in March it cut its main interest rate to a record low 0.1%. But Bailey said this level of central bank asset purchases "shouldn't always be taken for granted"."When the time..