[IOT-1517] Update scons scripts to pull gtest from github

[IOT-1517] Update scons scripts to pull gtest from github

Stop downloading gtest-1.7.0 from the fedora project mirror.
Download it from github googletest project page.

The major changes as a result are:
    - The name of the zip file has changed from
      gtest-1.7.0.zip to release-1.7.0.zip
    - The name of the extracted folder has changed from
      gtest-1.7.0 to googletest-release-1.7.0
    - Google test no longer contains a configure file to
      run auto make files. The autoreconfig tool is used
      to produce a new configure file from the
      configure.ac file.

Change-Id: I3316af1f3a875137a872577a22f0e4db74f0b0f3
Signed-off-by: George Nash <george.nash@intel.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/14381
Reviewed-by: Larry Sachs <larry.j.sachs@intel.com>
Reviewed-by: Phil Coval <philippe.coval@osg.samsung.com>
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Dan Mihai <Daniel.Mihai@microsoft.com>