By Echo Wang NEW YORK (Reuters) -Blackstone is weighing strategic options, including an initial public offering or a sale, for Ancestry.com, the hugely popular platform that helps users trace their genealogical roots, people familiar with the matter said. The buyout firm invited banks to pitch for an IPO of the Lehi, Utah-based company, the people said, asking not to be identified because the information is not public. Requests for proposals were submitted by the banks earlier this week, they added. A p ...