Collection resource not notifying its updated model when child resource is added...

Collection resource not notifying its updated model when child resource is added or removed.

- Updating "links" attribute in resource model of collection when resource is added to
   removed from collection.
- Changed from "Single resource" to "Simple resource" for maintaining UI consistency.
- Fix for compilation issue while compiling simulator in debug mode.
- Sending error response based on the schema provided in RAML file.

Change-Id: I33c1037f57128cdfacf10c06c2e3658bf0661f0e
Signed-off-by: Harish Kumara Marappa <h.marappa@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/4203
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: RadhaBhavani <radha.p@samsung.com>
Reviewed-by: Madan Lanka <lanka.madan@samsung.com>