NFL Owners passed a couple of rule changes Tuesday to wrap their meetings in New Orleans.   One involves controversial scoring plays.  Coaches will no longer be able to throw challenge flags on questionable TD's, disputes will go directly to the replay official in the press box.  The league's competition committee also tweaked rules on kickoffs.  Owners went along with the change to have the kick moved up five yards to the 35, cover units can only get a five yard running start downfield and touchbacks will still be placed at the 20, not the 25 as first proposed.  The Packers voted in favor of both changes.  The scoring replay vote was 30-2, the kickoff changes barely passed the 75 percent majority at 26-6.  Teams with skilled kickoff returners objected and considering the Packers have to kick to the likes of Devin Hester and Percy Harvin twice a year, easy to see why they voted for the change.  Hester told a Chicago radio station Tuesday the NFL should put Arena League nets up along the end line because there won't be many kickoffs run back.  Player safety was at the crux of the change, the league hopes to avoid high speed collissions on special teams but a special play, a kick return touchdown will become much harder to come by.  Teams will also be starting most drives at the 20 if not inside, forcing offenses to drive a minimum of 50 yards to get into scoring position.  80 yard touchdown drives are not easy to pull off and more field goals could be the end result of the rule changes.