""I'm no tame sigher, but a rampant lion of the forest,"" says Willmore, the Rover, on shore after a long voyage. ""I have a world of love in store,"" he claims, searching through the streets for a woman to prove it. When he meets two young Spanish woman-""I love mischief,"" says one-all the chemistry of comic satire lets loose. The Rover roamed the English stage for a century and has been rediscovered in our own time as a theatrical masterpiece of wit and daring. Aphra Behn (1640-1689) combined dramatic genius and training with personal experience that gave her rare insight into manners and roles. She spied on the Dutch for the English king and was once imprisoned for debt. Behn is one of the very few great English playwrights to be honored in life by popular scandal and in death by burial at Westminster Abbey. She was the first English woman to earn her living by writing.