Update Windows build to use zlib 1.2.1
diff --git a/PCbuild/readme.txt b/PCbuild/readme.txt
index 7832cb1..02227a2 100644
--- a/PCbuild/readme.txt
+++ b/PCbuild/readme.txt
@@ -117,15 +117,15 @@
 
 zlib
     Python wrapper for the zlib compression library.  Get the source code
-    for version 1.1.4 from a convenient mirror at:
+    for version 1.2.1 from a convenient mirror at:
         http://www.gzip.org/zlib/
-    Unpack into dist\zlib-1.1.4.
+    Unpack into dist\zlib-1.2.1.
     A custom pre-link step in the zlib project settings should manage to
-    build zlib-1.1.4\zlib.lib by magic before zlib.pyd (or zlib_d.pyd) is
+    build zlib-1.2.1\zlib.lib by magic before zlib.pyd (or zlib_d.pyd) is
     linked in PCbuild\.
     However, the zlib project is not smart enough to remove anything under
-    zlib-1.1.4\ when you do a clean, so if you want to rebuild zlib.lib
-    you need to clean up zlib-1.1.4\ by hand.
+    zlib-1.2.1\ when you do a clean, so if you want to rebuild zlib.lib
+    you need to clean up zlib-1.2.1\ by hand.
 
 bz2
     Python wrapper for the libbz2 compression library.  Homepage
diff --git a/PCbuild/zlib.vcproj b/PCbuild/zlib.vcproj
index 0a46340..1562836 100644
--- a/PCbuild/zlib.vcproj
+++ b/PCbuild/zlib.vcproj
@@ -3,6 +3,7 @@
 	ProjectType="Visual C++"
 	Version="7.10"
 	Name="zlib"
+	RootNamespace="zlib"
 	SccProjectName="zlib"
 	SccLocalPath="..">
 	<Platforms>
@@ -20,7 +21,7 @@
 			<Tool
 				Name="VCCLCompilerTool"
 				Optimization="0"
-				AdditionalIncludeDirectories="..\Include,..\PC,..\..\zlib-1.1.4"
+				AdditionalIncludeDirectories="..\Include,..\PC,..\..\zlib-1.2.1"
 				PreprocessorDefinitions="_DEBUG;WIN32;_WINDOWS"
 				RuntimeLibrary="3"
 				UsePrecompiledHeader="2"
@@ -36,7 +37,7 @@
 				Name="VCCustomBuildTool"/>
 			<Tool
 				Name="VCLinkerTool"
-				AdditionalDependencies="..\..\zlib-1.1.4\zlib.lib"
+				AdditionalDependencies="..\..\zlib-1.2.1\zlib.lib"
 				OutputFile="./zlib_d.pyd"
 				LinkIncremental="1"
 				SuppressStartupBanner="TRUE"
@@ -62,8 +63,8 @@
 			<Tool
 				Name="VCPreLinkEventTool"
 				Description="Checking static zlib has been built"
-				CommandLine="cd ..\..\zlib-1.1.4
-nmake -nologo -f msdos\makefile.w32 zlib.lib
+				CommandLine="cd ..\..\zlib-1.2.1
+nmake -nologo -f win32\Makefile.msc zlib.lib
 "/>
 			<Tool
 				Name="VCResourceCompilerTool"