General beast update, fixes, optimizations, features:

* Clean ups, optimizations, and new File::commonDocumentsDirectory enum
* Replace sortArray with std::sort for performance
* More error tolerance in XML parser, speedups
* Refactor some byte-order mark detection code
* Add String::appendCharPointer overloads
* More XML parser optimisations and better error detection
* Misc performance tweaks
* Fixes for support of non utf8 strings
* Increased precision when storing strings in XmlElement
* Minor clean-ups
* Minor fix to XmlDocument
* Cleanups to CriticalSection and related synchronization primitives
* Fix DynamicArray unit test

modules/beast_core/json/beast_JSON.cpp

@@ -311,7 +311,7 @@ private:
             buffer.appendUTF8Char (c);
         }
 
-        result = buffer.toString();
+        result = buffer.toUTF8 ();
         return Result::ok();
     }
 };
@@ -521,7 +521,7 @@ String JSON::toString (const var& data, const bool allOnOneLine)
 {
     MemoryOutputStream mo (1024);
     JSONFormatter::write (mo, data, 0, allOnOneLine);
-    return mo.toString();
+    return mo.toUTF8 ();
 }
 
 void JSON::writeToStream (OutputStream& output, const var& data, const bool allOnOneLine)