Welcome to this week’s Release Round-Up! America, Half Century (America Records/Gonzo) (Amazon U.S. / Amazon U.K. / Amazon Canada) The 50th anniversary celebration of America rolls on with a massive new box set. Half Century is an expansive 7-CD/1-DVD box packed with rare and previously unreleased material from the beloved band featuring Gerry Beckley, Dewey Bunnell, and the late Dan Peek. There’s a slew of unreleased demos circa 1970; a remastered full-length radio session in Bremen from 1973; rehearsals and demos for the Hideaway album; 11 unheard session recordings from 1981; a disc full of rarities…