Creditors of bankrupt Edwards Theaters Circuit must have breathed a sigh of relief Tuesday as they approved a bankruptcy reorganization plan that hands over control of the exhibitor to Philip Anschutz, the country's sixth richest man. Anschutz, who has also nabbed control of two other theater chains, United Artists and Regal, now commands more than 20 percent of the nation's theaters. Under the bankruptcy plan, creditors who want to be paid off now agreed to accept 90 cents on the dollar. Those willing to wait to be paid off over seven years, will receive all the money due. More important, Edwards will now be able to walk away from leases where theaters are performing poorly.