If there was a Toddler TRL, the Salteens would be huge stars, sell-outs in your eyes, who would no doubt make you feel morally superior. But there isn’t a Toddler TRL, there’s just my inbox. It seems like every other day I get an email from an imploring parent, asking the Salteens to please, please, please make their Yo Gabba Gabba song “I’m So Happy” available for download or purchase, or anything just so they can satisfy the unabating requests…