Support server side playlist access control exclusion
* only run when enableAccessControlExclusion var is set. 
* isAccessControlAllowed was only being run for entries, so not clear
why it had a request entry lookup; commented out, could warrant further
investigation.
push up entry result errors to top level playlist 

( else they are hidden under the assumption that its an empty entry )
Use base url in refer header checks ( seems to be causing issues )
break multi-request into 5 entries at a time ( seems to be hitting
multi-request API limits )
support getting named request count
include playlist headers in evaluating CDN cache headers of iframe
optimized ac check on per-ac profile basis not per entry
adds user agent to ac filter support.
Moved AC filter outside of playlist api call ( support mrss as well )
Merge branch 'serverside-ac-playlist-exclusion' into 2.13-July-13