As Syrian refugees continue to flee the violence at home, President Obama is turning to the modern tools of Silicon Valley entrepreneurship as a supplement to the more traditional means of humanitarian relief. At the request of officials from the White House Office of Digital Strategy, the crowdfunding website Kickstarter has begun its first social service campaign aimed at raising money for the United Nations refugee agency on behalf of Syrian refugees. Visitors to the site, which is better known for helping inventors and filmmakers, can contribute $15 to buy a sleeping bag, $70 for an emergency rescue …