Modifications per RI code review.

Modifications per RI code review.

- Add function missing headers
- Changed return type to bool where appropriate
- Declared functions that were only used in module as static

Change-Id: I6c4eb32714a5582b6237aa6ab624652c64929fb5
Signed-off-by: Doug Hudson <douglas.hudson@intel.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/617
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Mandeep Shetty <mandeep.shetty@intel.com>
Reviewed-by: Sachin Agrawal <sachin.agrawal@intel.com>
Reviewed-by: Erich Keane <erich.keane@intel.com>