Add network monitor support for Windows

Add network monitor support for Windows

Also fix a memory leak in the Linux code

Change-Id: I8d243604a49cf4f2947849ac13624b2c044259d5
Signed-off-by: Dave Thaler <dthaler@microsoft.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/12953
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Soemin Tjong <stjong@microsoft.com>
Reviewed-by: Dan Mihai <Daniel.Mihai@microsoft.com>
Reviewed-by: David Antler <david.a.antler@intel.com>
Reviewed-by: Ashok Babu Channa <ashok.channa@samsung.com>