Don't use JsonBuffer to create or parse objects and arrays.

* Added DynamicJsonArray and StaticJsonArray
* Added DynamicJsonObject and StaticJsonObject
* Added DynamicJsonVariant and StaticJsonVariant
* Added deserializeJson()
* Removed JsonBuffer::parseArray(), parseObject() and parse()
* Removed JsonBuffer::createArray() and createObject()

test/JsonParser/CMakeLists.txt

@@ -0,0 +1,15 @@
+# ArduinoJson - arduinojson.org
+# Copyright Benoit Blanchon 2014-2018
+# MIT License
+
+add_executable(JsonParserTests
+	JsonArray.cpp
+	JsonObject.cpp
+	JsonVariant.cpp
+	nestingLimit.cpp
+	StaticJsonArray.cpp
+	StaticJsonObject.cpp
+)
+
+target_link_libraries(JsonParserTests catch)
+add_test(JsonParser JsonParserTests)