Cycles: Direct multi light sampling in the Branched Path Integrator is optional now.

Disabling this can improve performance, when we need a lot of AA Samples anyway, to clear up the render.

Simple example .blend: http://www.pasteall.org/blend/27582

Differential Revision: https://developer.blender.org/D392

intern/cycles/blender/blender_sync.cpp

@@ -197,7 +197,8 @@ void BlenderSync::sync_integrator()
 #endif
 
 	integrator->method = (Integrator::Method)get_enum(cscene, "progressive");
-	
+
+	integrator->sample_all_lights_direct = get_boolean(cscene, "sample_all_lights_direct");
 	integrator->sample_all_lights_indirect = get_boolean(cscene, "sample_all_lights_indirect");
 
 	int diffuse_samples = get_int(cscene, "diffuse_samples");