Improve external library management error handling

Improve external library management error handling

Change-Id: I2a0b7003f0bd2987fa101285977fa0621688017b
Signed-off-by: Caiwen Zhang<caiwen.zhang@intel.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/327
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Patrick Lankswert <patrick.lankswert@intel.com>
(cherry picked from commit c824277b602590f2f4af8b553106b6913e62fad2)
Reviewed-on: https://gerrit.iotivity.org/gerrit/388
Reviewed-by: Sudarshan Prasad <sudarshan.prasad@intel.com>