Fix auto_build.py on Python 2.7.10 for Windows

Fix auto_build.py on Python 2.7.10 for Windows

There are two fixes in this build.

* Prior to this change, Python was putting quotes around the SCons call.
  This behavior differs from Python 2.7.0.

* Prior to this change, "python auto_build.py" would try to build Android
  and fail.  Now we limit auto_build.py to only build Windows binaries on
  a Windows host.

Change-Id: I41ec4986c3dc57821cfdbe48f598e547e1934c71
Signed-off-by: David Antler <david.a.antler@intel.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/12841
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Ajay Saini <ajay.saini@intel.com>
Reviewed-by: Mike Fenelon <mike.fenelon@microsoft.com>
Reviewed-by: Dave Thaler <dthaler@microsoft.com>