Gin and soda,” I tell the waiting bartender. “Gin and tonic?” she smirks. “Nope,” I repeat. “Gin and soda.” I’m killing time at the Meridian (1503 Chartres), waiting for 2007 Warped Tour co-headliners and pseudobilly superstars Tiger Army. Imperative Reaction just finished and Boston’s Street Dogs are setting up. Like most everyone…