THREE BOULEVARD FORCES by Georges Feydeau; translated with an introduction by John Mortimer; (Penguin: $5.95, paperback). That doyen of bedroom farce, Georges Feydeau (1862-1921), who has consistently fattened box- office receipts by delighting theater audiences over the last 100 years with his wit, wild invention and irreverence, ranked as merely an adroit fashioner of light entertainment until the 1940s when his best work began to find a place in the repertoires of such prestigious companies as the Comedie-Francaise. Feydeau has by now secured a place among the great masters of the ingenious plot and comic situation. He even has been called the greatest French dramatist since Moliere. High praise! Penguin Books--that BBC of publishing--has happily added this volume containing "A Little Hotel on the Side," "A Flea in Her Ear" and "The Lady From Maxim's" to its Penguin Plays list. The three are among Feydeau's most popular farces and each a powder keg of hilarity whether seen or read. All target the peccadilloes and pretensions of the bourgeois who are brought to their knees during the course of Feydeau's madcap rush of mishaps, mix-ups and misadventures, yet--fear not--everything turns out all right in the end. Comedy, mai oui ! Translator Mortimer, widely known for his own "Rumpole of the Bailey," and his TV adaptation of Evelyn Waugh's "Brideshead Revisited," that svelte melodrama on God, money, companionship and booze, has given us an up-dated but generic Feydeau.