2.5.x features

shows, show-schedules, show-preview, show-history-feed, item-history-feed endpoints to the HTTP api to be used via NewscoopAirtimePlugin

These endpoints are needed for airtime pro instances and should be merged to saas branch.
Yeah, I thought the same, infact for most of these models, seems like an extra layer of abstraction.    I'm still not clear exactly how the separation of code logic is supposed to be here, but I've revised my code and removed dependency on Show.php model all together.