SUNNYVALE, California (AP) — Hundreds of years ago, Yemen helped introduce the world to coffee. Lately, the mountainous, war-ravaged country that borders Saudi Arabia and Oman is exporting something else: its coffee culture. Yemeni coffeehouses are opening at a rapid pace across the U.S. The number of cafes run by six major chains that serve Yemeni-style drinks grew 50% last year to 136, according to Technomic, a restaurant industry consulting company. The count doesn’t include the many smaller