update install instructions for windows

Mostly removed some of the info about node-gyp and refer instead to the node-gyp page which is kept up to date for newer versions of Windows.

README.md

@@ -103,24 +103,14 @@ node ./test/test.js
 On Windows, you'll need to install some dependencies first:
  - [OpenSSL](http://slproweb.com/products/Win32OpenSSL.html) (normal, not light)
 in the same bitness as your Node.js installation.
-  - The build script looks for OpenSSL in the default install directory  
-  (`C:\OpenSSL-Win32` or `C:\OpenSSL-Win64`)
-  - If you get `Error: The specified module could not be found.`, copy `libeay32.dll` from the OpenSSL bin directory to this module's bin directory, or to Windows\System3.
- - [node-gyp](https://github.com/TooTallNate/node-gyp/) (`npm install -g node-gyp`)
-   - [Python 2.7](http://www.python.org/download/releases/2.7.3#download) (not 3.3)
-   - Microsoft Visual Studio C++ _**(either of the two below but not both)**_
-        - `Microsoft Visual Studio C++ 2013 for Windows Desktop` ([Express](http://www.microsoft.com/en-au/download/details.aspx?id=40787) version works well)
-            - No extra patches should be needed, but requires a fully up-to-date machine including all of the latest service packs
-        - Older versions of Visual Studio
-            - Windows XP/Vista/7:
-                - `Microsoft Visual Studio C++ 2010` ([Express](http://go.microsoft.com/?linkid=9709949) version works well)
-                    - For 64-bit builds of node and native modules you will _**also**_ need the [Windows 7 64-bit SDK](http://www.microsoft.com/en-us/download/details.aspx?id=8279)
-                    - If you get errors that the 64-bit compilers are not installed you may also need the [compiler update for the Windows SDK 7.1](http://www.microsoft.com/en-us/download/details.aspx?id=4422)
-            - Windows 8:
-                - `Microsoft Visual Studio C++ 2012 for Windows Desktop` ([Express](http://go.microsoft.com/?linkid=9816758) version works well)
-
-
-
+  - OpenSSL must be installed in the a specific install directory (`C:\OpenSSL-Win32` or `C:\OpenSSL-Win64`)
+  - If you get `Error: The specified module could not be found.`, copy `libeay32.dll` from the OpenSSL bin directory to this module's bin directory, or to Windows\System32.
+ - [node-gyp](https://github.com/nodejs/node-gyp) (`npm install -g node-gyp`)
+   - You will need [python 2.7](http://www.python.org/download/releases/2.7.3#download) and a compatible version 
+  Visual Studio installed first.  Even with that, `node-gyp` installation or use can have 
+  issues on Windows.  The `node-gyp` [README file](https://github.com/nodejs/node-gyp) has detailed instructions 
+  if you have difficulties.  [This post](https://www.robertkehoe.com/2015/03/fix-node-gyp-rebuild-error-on-windows/) 
+  is also a good reference.
 
 Usage
 -----