deps: Add nlohmann json

I decided to go with nlohmann::json because it supports both JSON and
msgpack. I'm likely going to have to write some conversion utils to
convert between obs_data_t and json, but the advantages of what
nlohmann::json brings to the table are just too attractive.

.gitmodules

@@ -4,3 +4,6 @@
 [submodule "deps/asio"]
 	path = deps/asio
 	url = https://github.com/chriskohlhoff/asio.git
+[submodule "deps/json"]
+	path = deps/json
+	url = https://github.com/nlohmann/json.git

CMakeLists.txt

@@ -51,6 +51,11 @@ find_package(LibObs REQUIRED)
 find_package(Qt5 REQUIRED COMPONENTS Core Widgets Concurrent)
 
 
+# Find nlohmann
+set(JSON_BuildTests OFF CACHE INTERNAL "")
+add_subdirectory(deps/json)
+
+
 # Configure files
 configure_file(
 	src/plugin-macros.h.in
@@ -99,7 +104,8 @@ target_link_libraries(obs-websocket
 	libobs
 	Qt5::Core
 	Qt5::Widgets
-	Qt5::Concurrent)
+	Qt5::Concurrent
+    nlohmann_json::nlohmann_json)
 
 
 # Windows-specific build settings and tasks

src/WebSocketServer.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <QObject>
+#include <nlohmann/json.hpp>
 
 #include "requesthandler/RequestHandler.h"
 
@@ -10,4 +11,7 @@ class WebSocketServer : public QObject
 
 	public:
 		;
+
+	private:
+		;
 };

src/requesthandler/rpc/Request.h

@@ -1 +1,3 @@
-#pragma once
+#pragma once
+
+#include <nlohmann/json.hpp>

src/requesthandler/rpc/RequestResult.h

@@ -1 +1,3 @@
-#pragma once
+#pragma once
+
+#include <nlohmann/json.hpp>