Update for Visual studio 2013

The order of the includes needed a change to support the latest version of the Cygwin download. That introduced compilation errors for the Visual studio build. In this new release, the order of the include files is adjusted to make it build on all platforms.
The difference between this version and the one on Yahoo-TWS is only one #include statement.

Initial Release of version 9.71

Initial Master release of TwsApiC++ version 9.71 on Github