Refactored to use StringBuilder

srcs/StringBuilder.cpp

@@ -0,0 +1,17 @@
+/*
+ * Arduino JSON library
+ * Benoit Blanchon 2014 - MIT License
+ */
+
+#include "StringBuilder.h"
+
+using namespace ArduinoJson::Internals;
+
+size_t StringBuilder::write(uint8_t c)
+{
+    if (length >= capacity) return 0;
+
+    buffer[length++] = c;
+    buffer[length] = 0;
+    return 1;
+}