*Williams hosts first Under-18 national team camp; U.S. U-19s head to Germany
*Cabrera out as U.S. Under-17 coach
*Johnson let go by Puebla due to lack of fitness
*Salgado, Gil among 36 players called in to U.S. Under-20 training camp
*Friedel still hard to beat at home
*Gomez has dream debut with Santos
