HPCC-9407 Add support for building in VS2012

Fixes HPCC-9407

Signed-off-by: Gordon Smith <gordon.smith@lexisnexis.com>
Merge pull request #4433 from GordonSmith/HPCC-9407

HPCC-9407 Add support for building in VS2012

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>