Olivine Diamond Head   Formerly known as Diamond Head Grill (and still known as such to most), the newly renamed Olivine Diamond Head got a new name this year, as well as a new chef. Former chef — and creator of the restaurant's French-inspired contempo American menu — Mariano Lalica has moved on, leaving Olivine in the capable hands of his protege, Elton Idica.  2885 Kalakaua Ave., second floor. 922-3734, 6:30 10:30 a.m.; 6-10 p.m. nightly. Bar: 5:30 p.m.-midnight Sundays-Thursdays, 5:30 p.m.-2 a.m. Fridays-Saturdays. Reservations recommended. Valet and self-parking. AX, DC, DS, JCB, MC, VS. No checks. Breakfast: $$. Dinner: $$$$.  Web site: www.w-dhg.com