PRECIOUS-Gold rises, set for biggest weekly gain since mid-April

May 19 (Reuters) - Gold prices edged higher early Friday and were on track for their biggest weekly gain since mid-April as the dollar softened and stocks eased amid the ongoing political crisis in the United States that weakened risk appetite. FUNDAMENTALS * Spot gold rose 0.3 percent to $1,250.20 per ounce by 0102 GMT. It slipped 1.1 percent on Thursday in its biggest one-day percentage drop since May 3 to snap a five-day rally. The yellow metal was up about 1.8 percent