Eighties indie-rockers the Replacements are usually thought to have been a brilliant, messily spectacular unit until they jumped to a major label, mellowed out, and started sucking. Nonsense — Rhino’s recent remastering of the band’s four Warner Bros. albums represents something far from a case of flagging inspiration. The post–Let It Be discs show front man Paul Westerberg figuring out how to evolve from an unhappy kid into an unhappy adult, in messily spectacular and often brilliant ways.