Implement support for complex obs

This will allow clients to post complex observations and the data via REST, this depends on first completing TRUNK-4964. The handlers in core i.e ImageHandler, MediaHandler and BinaryDataHandler assume that clients will send the complex obs data as uuencoded text, module custom handlers will need to be updated to be able to support this, they don't have to use uuencoding, i.e they can use other mechanisms e.g URI as references to where the Obs Data is stored as one of the alternatives especially where large objects have to be submitted. The TextHandler in core will still accept plain text instead of uuencoded strings.

Dev Notes

• Update ObsResource1_8.setValue to delegate to Obs handler to set the complex data by calling the new method added in TRUNK-4964

• Update ObsResource1_8.setValue(Obs obs, Object value) to return the serializable value with the URI to be used by clients to fetch the raw complex value, see snippet below

  if (obs.getValueComplex() != null) {
         SimpleObject so = new SimpleObject();
         so.put("display": "some human readable value");// Obs.getValueAsString(Locale) might work
         SimpleObject links = new SimpleObject();
         links.put("rel", "self");
         //Can be got by calling ObsService.getComplexObs(Obs, ComplesObsHandler.URI_VIEW)
         links.put("uri", "uri-to-fetch-raw-complex-value");
         so.put("links", links);
         return so;
  }