Vikings officials say they’re getting closer to signing their draft picks.  The team and agents for the draftees exchanged contract proposals yesterday.  With players reporting to Mankato tomorrow for training camp, the Vikings have yet to sign any of their five draft picks. Their top selection was at number 43 overall was Tyrell Johnson, who played safety at Arkansas State.  They had the 17th overall selection, but traded it to Kansas City in exchange for defensive end Jared Allen.  The Chiefs then dealt the pick to Detroit, who selected Boston College offensive lineman Gosder Cherlius.