setuptools 25.1.4 adds extra quotes on LIBPATH

[minrk]

#715's quoting has caused my appveyor builds to start failing with 25.1.4, due to some extra quoting.

With setuptools 25.1.3, builds succeed, and with 25.1.4 they fail.

The key difference:

on 25.1.3, the link command had args like:

"/LIBPATH:C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\LIB"

on 25.1.4, they look like:

"/LIBPATH:"C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\LIB""

(note the extra quotes).

These are CPython 3.5 x86 builds on appveyor; I don't know what other versions are affected.

[ft1337]

CPython 3.5 amd64 builds on Windows fail, too.

[anthrotype]

sorry, I was too fast. It's actually still not working for me either, even after #723.
I probably had incorrectly installed setuptools from the PR branch.

Before #723 was merged, I would get something like this:

"/LIBPATH:"C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\LIB""

after #723 I get this:

""/LIBPATH:C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\LIB""