JSON Object implementation

JSON Object implementation

1. Support for JSON object in OCRepresentation.
2. Code refactor for JSON composition in various parts of the stack into one place (OCRepresenation).
3. Similar code refactoring for JSON parsing needs to be done. I will revisit when we look into
   JSON parse library alternatives.
4. Implemented correct JSON composition. Earlier we were returning strings for all the json types.
   Now strings are only used for string types and JSON objects.
5. garageserver.cpp and garageclient.cpp examples to explain the user of JSON object with in
   the representation.

Change-Id: I9461db811c7b5e3b827d5704cde489aa2005e291