NEW YORK — It has been a wild and in some cases wacky season for network TV, culminating in a hunt for millions of missing viewers that is so complicated that it’s worthy of its own episode of ‘CSI.’ On the surface, it is status quo — CBS extended its winning streak in total viewers to five years, while ‘American Idol’-powered Fox bagged a third consecutive season victory among adults 18-49. But underneath, a sea change has been brewing. ‘I think we’ll look back and see 2007 as the watershed when all the things we talked about — viewing behavior and audience measurement of that behavior — all came together to start the new era,’ NBC research chief Alan Wurtzel said. ‘We’ve talked a lot about change and everything, but this is the first year we’ve seen it in a profound way.’ At the beginning of the season, Nielsen Media Research introduced ‘most current’ ratings, cuming the audiences that watch a show live as well as those that record it on a DVR and watch it up to seven days later. But even with those additional viewers counted this season, primetime television viewing dropped […]