ui/handler: Implement UI Handler interface class

Adds the ability to override the UI for very specific encoders in order to properly support customized and detailed UI for each encoder. This design is flexible and allows for any kind of UI generator to work, without relying on an actual object too much.

source/ui/handler.cpp

@@ -0,0 +1,18 @@
+// FFMPEG Video Encoder Integration for OBS Studio
+// Copyright (C) 2018 - 2019 Michael Fabian Dirks
+//
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This program 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 General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+
+#include "handler.hpp"