directory re-organization (keeps the old build system)

there is no internal modification of any file in this commit

files are moved into directories according to established standards in
sourcecode distribution; these directories contain:

 src - Files that are used in constructing the executable binaries,
       but are not installed.

 doc - Files in HTML and text format that document usage, quirks of
       the implementation, and contributor checklists.

 locale - Files that contain human language translation of strings
          used in the program

 contrib - Files contributed from distributions or other third party
 	   implementing scripts and auxiliary programs

src/json/json_spirit.h

@@ -0,0 +1,18 @@
+#ifndef JSON_SPIRIT
+#define JSON_SPIRIT
+
+//          Copyright John W. Wilkinson 2007 - 2009.
+// Distributed under the MIT License, see accompanying file LICENSE.txt
+
+// json spirit version 4.03
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1020)
+# pragma once
+#endif
+
+#include "json_spirit_value.h"
+#include "json_spirit_reader.h"
+#include "json_spirit_writer.h"
+#include "json_spirit_utils.h"
+
+#endif