George Bernard Shaw famously dubbed Shakespeare's Cymbeline "stagey trash of the lowest melodramatic order." Appalled by the ludicrous coincidences and tangled plot lines, Shaw rewrote the last act of the play, which he titled Cymbeline Refinished. The playlet premiered in London in 1937. A new version of Cymbeline, playing at Classic Stage Company's Lynn F. Angelson Theater and presented by NAATCO in partnership wit…