Modified discovery payload to be spec compliant.

Modified discovery payload to be spec compliant.

The discovery oic/res payload had the device id "di" and "links"
being repeated for every resource. The payload itself was not structured
in a spec compliant way.

Plucked out di and links from every resource and put in the root map.
The format for the payload is "modelled" as JSON.
[
    {
        "di" : UUID,
        links :[
                    {
                        href, rt, if, policy        // Resource 1
                    },
                    {
                        href, rt, if, policy        // Resource 2
                    },
                    .
                    .
                    .
                ]
    }
]

Change-Id: I2c50a7cc1ee46df633810372e446ac92c5e496f5
Signed-off-by: Mandeep Shetty <mandeep.shetty@intel.com>
Signed-off-by: Joseph Morrow <joseph.l.morrow@intel.com>
Signed-off-by: Mandeep Shetty <mandeep.shetty@intel.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/4543
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Markus Jung <markus.jung85@gmail.com>
Reviewed-by: Jon A. Cruz <jonc@osg.samsung.com>