Fifteen years ago, Aydin Senkut, a former Google exec, was an outsider in venture circles that didn’t take seriously his ambitions to become a top VC. Now, his firm, Felicis Ventures, is announcing $900 million in capital commitments across two new funds — a $600 million early-stage fund and a $300 million opportunities-type fund to back its fastest-growing winners — and its limited partners would have preferred that the firm raise even more.