Update template, add comment and message about Windows build
diff --git a/templates/binding.gyp.template b/templates/binding.gyp.template
index 71276e7..650670b 100644
--- a/templates/binding.gyp.template
+++ b/templates/binding.gyp.template
@@ -39,29 +39,45 @@
   # Some of this file is built with the help of
   # https://n8.io/converting-a-c-library-to-gyp/
   {
-    'variables': {
-      'config': '<!(echo $CONFIG)'
-    },
-    # TODO: Finish windows support
     'target_defaults': {
-        # Empirically, Node only exports ALPN symbols if its major version is >0.
-        # io.js always reports versions >0 and always exports ALPN symbols.
-        # Therefore, Node's major version will be truthy if and only if it
-        # supports ALPN. The output of "node -v" is v[major].[minor].[patch],
-        # like "v4.1.1" in a recent version. We use cut to split by period and
-        # take the first field (resulting in "v[major]"), then use cut again
-        # to take all but the first character, removing the "v".
-      'defines': [
-        'TSI_OPENSSL_ALPN_SUPPORT=<!(node --version | cut -d. -f1 | cut -c2-)'
-      ],
       'include_dirs': [
         '.',
         'include'
       ],
       'conditions': [
         ['OS == "win"', {
-          "include_dirs": [ "third_party/boringssl/include" ]
-        }, {
+          "include_dirs": [ "third_party/boringssl/include" ],
+          "defines": [
+            '_WIN32_WINNT=0x0600',
+            'WIN32_LEAN_AND_MEAN',
+            '_HAS_EXCEPTIONS=0',
+            'UNICODE',
+            '_UNICODE',
+            'NOMINMAX',
+            'OPENSSL_NO_ASM'
+          ],
+          "msvs_settings": {
+            'VCCLCompilerTool': {
+              'RuntimeLibrary': 1, # static debug
+            }
+          },
+          "libraries": [
+            "ws2_32"
+          ]
+        }, { # OS != "win"
+            # Empirically, Node only exports ALPN symbols if its major version is >0.
+            # io.js always reports versions >0 and always exports ALPN symbols.
+            # Therefore, Node's major version will be truthy if and only if it
+            # supports ALPN. The output of "node -v" is v[major].[minor].[patch],
+            # like "v4.1.1" in a recent version. We use cut to split by period and
+            # take the first field (resulting in "v[major]"), then use cut again
+            # to take all but the first character, removing the "v".
+          'defines': [
+            'TSI_OPENSSL_ALPN_SUPPORT=<!(node --version | cut -d. -f1 | cut -c2-)'
+          ],
+          'variables': {
+            'config': '<!(echo $CONFIG)'
+          },
           'include_dirs': [
             '<(node_root_dir)/deps/openssl/openssl/include',
             '<(node_root_dir)/deps/zlib'
@@ -95,6 +111,22 @@
     'conditions': [
       ['OS == "win"', {
         'targets': [
+          {
+            # IMPORTANT WINDOWS BUILD INFORMATION
+            # This library does not build on Windows without modifying the Node
+            # development packages that node-gyp downloads in order to build.
+            # Due to https://github.com/nodejs/node/issues/4932, the headers for
+            # BoringSSL conflict with the OpenSSL headers included by default
+            # when including the Node headers. The remedy for this is to remove
+            # the OpenSSL headers, from the downloaded Node development package,
+            # which is typically located in `.node-gyp` in your home directory.
+            'target_name': 'windows_build_warning',
+            'actions': [
+              {
+                'message': "IMPORTANT: Due to https://github.com/nodejs/node/issues/4932, to build this library on Windows, you must first remove <(node_root_dir)/include/node/openssl/"
+              }
+            ]
+          },
           # Only want to compile BoringSSL and zlib under Windows
           % for module in node_modules:
           % for lib in libs:
@@ -117,8 +149,7 @@
               % for source in lib.src:
               '${source}',
               % endfor
-            ],
-            "include_dirs": [ "third_party/boringssl/include" ]
+            ]
           },
           % endif
           % endfor