IoTivity Simulator System testing bug fixes.

IoTivity Simulator System testing bug fixes.

1. Resolved issues found during stress testing.
2. Limiting the maximum number of resources that can be created
   from server to 200(Considering block-wise transfer and application
   stability).
3. Includes minor optimization and code clean-up.

Change-Id: If196b72b5221e3795b4693f00a99d33650c0a8d0
Signed-off-by: G S Senthil Kumar <senthil.gs@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/4431
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Radha Bhavani <radha.p@samsung.com>
Reviewed-by: Madan Lanka <lanka.madan@samsung.com>