add missing version_info.py for vc11 build

build.vc11/version_info.py

@@ -0,0 +1,13 @@
+
+# returns: 
+#   solution file version
+#   visual studio version
+#   microsoft compiler version
+#   microsoft compiler version (long)
+#   vcx project tools version
+vs_info = { 'solution':'12',
+            'visual studio':'2012',
+            'msvc':'11',
+            'msvc_long':'11',
+            'vcx_tool':'4.0'
+          }