Task/iotcore 127 documentation

Changes in the documentation to reflect information about deployment and operation and changes in the Access Control API.
The reationship between "prefix tokens" (i.e. "551" and "833") and the service/subservice concept is clearly explained. I would do the same with the concept of "resource" (I mean, telling that in the case of PEP for Orion CB, a resource equals to an entity... the term "resource" as is can be confusing for Orion API users).