Check Range header for stale content
Check Range header for stale content

 Fix bug:
    1. Ats cached a stale content
    2. Then we set cache.config  making  this content never-cache
    3. We send a request to ats for this content with a Range header
    4. ATS send a request to os with ims header
    5. The os returned 304 to ats
    6. ATS return 200  to client.

bryancall/trafficserver,SolidWallOfCode/trafficserver,vmamidi/trafficserver,pbchou/trafficserver,bryancall/trafficserver,duke8253/trafficserver,pbchou/trafficserver,duke8253/trafficserver,duke8253/trafficserver,SolidWallOfCode/trafficserver,pbchou/trafficserver,SolidWallOfCode/trafficserver,pbchou/trafficserver,SolidWallOfCode/trafficserver,duke8253/trafficserver,vmamidi/trafficserver,vmamidi/trafficserver,SolidWallOfCode/trafficserver,vmamidi/trafficserver,vmamidi/trafficserver,bryancall/trafficserver,pbchou/trafficserver,bryancall/trafficserver,bryancall/trafficserver,duke8253/trafficserver,bryancall/trafficserver,duke8253/trafficserver,pbchou/trafficserver,duke8253/trafficserver,SolidWallOfCode/trafficserver,SolidWallOfCode/trafficserver,vmamidi/trafficserver