Renamed all references to ‘/oc/core’ to ‘/oic/res’ and '/oc to /oic'

Renamed all references to ‘/oc/core’ to ‘/oic/res’ and '/oc to /oic'

This change set is based on OIC core framework standard specification draft A.
Modified reserved namespace to ‘/oc/core’ to ‘/oic/res’ and '/oc to /oic' for
discovery, including core framework, unit tests and samples.

Change-Id: I9721a2a70fd1e3245088b8a2f6366853db849b21
Signed-off-by: Moumita Ray <moumita.ray@intel.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/953
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Erich Keane <erich.keane@intel.com>