Add mac-syphon plugin

Allows adding Syphon servers as sources, and provides game-capture if
used with SyphonInject (specifically the scripting additions have to be
installed for SyphonInject to work from within OBS)

plugins/mac-syphon/plugin-main.c

@@ -0,0 +1,12 @@
+#include <obs-module.h>
+
+OBS_DECLARE_MODULE()
+OBS_MODULE_USE_DEFAULT_LOCALE("syphon", "en-US")
+
+extern struct obs_source_info syphon_info;
+
+bool obs_module_load(void)
+{
+	obs_register_source(&syphon_info);
+	return true;
+}