Stevie Nicks and Lindsey Buckingham have again invigorated the Fleetwood Mac fandom. Both music legends – who have been part of the seminal ’70s-era rock band – separately posted song lyrics on their individual X pages Thursday morning, sparking a flurry of excitement and hope online that the notoriously on-again-off-again musical cohorts would rejoin forces once more. “And if you go forward…” Nicks posted on her X page, before Buckingham posted a call-and-answer reply a half hour later,