Writer/director J.C. Chandor is counting his blessings. After struggling as a docu and commercial helmer, Chandor landed an original screenplay nom for his first feature “Margin Call,” a insider’s view of the financial meltdown starring Jeremy Irons.Chandor knew there was big news when his Blackberry started ringing non-stop after dropping is daughter off for school. But he had to deal with some domestic reality when his babysitter failed to show up on time. “I got an honest dose of humbleness because my one-and-a-half-year-old couldn’t care less about the Oscars. I was chasing him around and changing diapers,” Chandor said.