Add Windows build instructions

Author: FreddieAkeroyd

README.rst

@@ -124,3 +124,26 @@ programs (if configured to build them). To build the API documentation use
 
     $ make html
     $ make install-html
+
+Building the code on Windows
+============================
+
+These instructions will build everything except the applications using LIBXML2 (e.g. nxtranslate)
+
+* Download and install HDF4 and/or HDF5 libraries from HDF web site
+  * within these installations is a "cmake" directory, I needed to remove/rename this to get everything to configure properly
+* Download MXML source from http://www.msweet.org/projects.php?Z3
+  * open the vcnet directory
+  * you need to edit mxml1.def and a add a single line containing the text    mxml_error   to the end of this file
+  * open the visual studio solution and build the project
+  * copy the files mxml.h mxml1.lib mxml1.dll to some other location
+* Define HDF4_ROOT, HEF5_ROOT and MXML_ROOT environment variables to point to top of each installed area
+  * you should use / rather than \ for the paths specified in these variables
+* Create an empty build directory somewhere - this can be within your nexus source tree
+* Run CMAKE-GUI to generate Visual studio solutions files
+  * Provide source and build paths in the relevant boxes
+  * Click on Configure, choose appropriate visual studio version when prompted
+  * A list of options will appear, choose the appropriate ENABLE_ ones and press Configure again
+  * If nothing is red, click on Generate
+* Browse to the build directory and open the generated NeXus.sln
+* Build the solution