Packaging: remove last mentions and uses of setup.py in the code.

Now only the compatibility layer (in create, util and install) talk
about setup.py.
diff --git a/Lib/packaging/compiler/msvccompiler.py b/Lib/packaging/compiler/msvccompiler.py
index 97f76bb..3d4ac3c 100644
--- a/Lib/packaging/compiler/msvccompiler.py
+++ b/Lib/packaging/compiler/msvccompiler.py
@@ -134,8 +134,7 @@
 """Python was built with Visual Studio 2003; extensions must be built with
 a compiler than can generate compatible binaries. Visual Studio 2003 was
 not found on this system. If you have Cygwin installed, you can try
-compiling with MingW32, by passing "-c mingw32" to setup.py.""")
-# XXX update this comment for setup.cfg
+compiling with MingW32, by passing "-c mingw32" to pysetup.""")
 
         p = r"Software\Microsoft\NET Framework Setup\Product"
         for base in HKEYS: