A Fashion History Lesson...Marc Jacobs Perry Ellis Grunge Redux, and 80's Vegas Hookers? Yep, It's Project Runwaaaayyyyyy!! Bianca Jagger, 1970s, in Halston one-shoulder dress This past Thursday on Project Runway Season 9, for the 10th Episode, the remaining designers were given a task: To create two looks that were "Inspired by the Sophisticated 70's". Many of them had quite a problem A) Knowing WHAT the 1970's were and B) Knowing what the "Sophisticated 70's" looked like. For some, BOTH of…