removed TokenAuthentication class and added ability to store and read custom response headers on each httprequest vo created.
Added RequestModifierExtensions that all request pass through that can be extended so requests can be modified by a user as they may wish.
Fixed bug with URIQery...Model
added required import to dash if player index.html
Merge pull request #317 from AkamaiDASH/development

Abstracted out the TokenAuthentication class...