Add a maximum presence TTL of 24 hours

Add a maximum presence TTL of 24 hours

- Set TTL to max TTL if TTL exceeds max TTL.
- Rename static function to make name reflect what the function
  actually does.
- Change function signature so that float casts can be removed.
- Add guards against overflowing a uint32_t argument.

Change-Id: Ie391f96fa153b48771187ea6b3d5cf718f52cb52
Signed-off-by: Doug Hudson <douglas.hudson@intel.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/819
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Joseph Morrow <joseph.l.morrow@intel.com>
Reviewed-by: Erich Keane <erich.keane@intel.com>