After a prolonged delay, the National Lampoon’s Vacation reboot is back on. In the new installment of the franchise made famous by Chevy Chase and Beverly D’Angelo, Ed Helms will play an adult Rusty Griswold, who decides to take his own family on vacation like the ones his father Clark used to lead. Christina Applegate, Chris Hemsworth and Charlie Day are also in talks for the comedy. Never fear, Sparky fans, according to The Hollywood Reporter, Chase and D’Angelo will both be featured in cameos …