Allow multiple libraries in Submitted/Approved state in Launch

[#1]

We often find ourselves blocked when a piece of content is held up in approval or validation and we need to hotfix something or even just push through some unrelated bit of code. I understand the desire to minimize conflicting edits, but sites have so much content that the odds of two libraries conflicting seem pretty slim. We'd really like to see the publishing flow look more like a version control system and not have hard blockers - or at least increase the limit from 1.