Last month at VidCon, an annual gathering of almost video creators and fans at the Anaheim Convention Center in California, every major player in social media announced new initiatives to embrace the next generation of viral video makers. Instagram showed off a feature that would let followers access a livestream for up to 24 hours. YouTube announced a production tool called VR180 that makes it easy for people to create and share 3-D videos in 180 degrees. (All you need is one of the special cameras due later this year from LG, Lenovo, and YI Technology.) And Facebook unveiled updates