On the 1.8.x-VS2013-14 branch: Set the right informational version for
Visual Studio 2013.

The rest of the original patch really allows Visual Studio to ignore this
number by creating a proper version independent solution file for VS2010 and
later, so this is just a minor fix.

* branches/1.8.x/build/generator/gen_win.py
  (parse_options): Don't use 2012 as informational version for VS 2013.


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/1.8.x-VS2013-14@1606751 13f79535-47bb-0310-9956-ffa450edef68