OREGON LIBERALS UPSET BY PROGRAM TO KEEP YOUNG WOMEN ADDICTS FROM GETTING PREGNANT COVER STORY:The Fix How do you keep an addict from getting pregnant? Pay her. by AMY ROE Last month, Heather Keithley, 21, went to Planned Parenthood on Northeast Fremont Street. Inside the clinic she lay down on an exam table, her straight, reddish-brown hair splayed out behind her. She tried not to flinch as a small, T-shaped stick was inserted into her vagina and, finally, her uterus. She was getting an IUD. And, because Keithley is a recovering speed freak, she'll also get $200 from a California...