Switch out jsoncpp for nlohmann json

Add llsdjson.* too!

indra/llcommon/llsdjson.h

@@ -0,0 +1,77 @@
+/** 
+ * @file llsdjson.cpp
+ * @brief LLSD flexible data system
+ *
+ * $LicenseInfo:firstyear=2015&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2015, Linden Research, Inc.
+ * 
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ * 
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+ * $/LicenseInfo$
+ */
+
+#ifndef LL_LLSDJSON_H
+#define LL_LLSDJSON_H
+
+#include <map>
+#include <string>
+#include <vector>
+
+#include "stdtypes.h"
+
+#include "llsd.h"
+#include <nlohmann/json.hpp>
+
+/// Convert a parsed JSON structure into LLSD maintaining member names and 
+/// array indexes.
+/// JSON/JavaScript types are converted as follows:
+/// 
+/// JSON Type     | LLSD Type
+/// --------------+--------------
+///  null         |  undefined
+///  integer      |  LLSD::Integer
+///  unsigned     |  LLSD::Integer
+///  real/numeric |  LLSD::Real
+///  string       |  LLSD::String
+///  boolean      |  LLSD::Boolean
+///  array        |  LLSD::Array
+///  object       |  LLSD::Map
+///  
+/// For maps and arrays child entries will be converted and added to the structure.
+/// Order is preserved for an array but not for objects.
+LLSD LlsdFromJson(const nlohmann::json &val);
+
+/// Convert an LLSD object into Parsed JSON object maintaining member names and 
+/// array indexs.
+/// 
+/// Types are converted as follows:
+/// LLSD Type     |  JSON Type
+/// --------------+----------------
+/// TypeUndefined | null
+/// TypeBoolean   | boolean
+/// TypeInteger   | integer
+/// TypeReal      | real/numeric
+/// TypeString    | string
+/// TypeURI       | string
+/// TypeDate      | string
+/// TypeUUID      | string
+/// TypeMap       | object
+/// TypeArray     | array
+/// TypeBinary    | unsupported 
+nlohmann::json LlsdToJson(const LLSD &val);
+
+#endif // LL_LLSDJSON_H