Refined Visual Studio 2013 Builds

* Project file factored into non-redundant properties files for ease of maintenance.
* Restructured file locations to ensure no conflict when building multiple configurations.
* Build info added to output.
* Configuration parameters refined.
* Fixed a number of x64 numeric inconsistencies (although some remain).
* Cosmetic fixes and fixes for some trivial compiler warnings.
* NuGet dependencies are not yet available in `v120` compilation so may fail at run time.
* Until they are updated, NuGet dependencies require updated targets to link, see:
    * [openssl-nuget-targets](https://github.com/evoskuil/openssl-nuget-targets)
    * [zlib-nuget-targets](https://github.com/evoskuil/zlib-nuget-targets)