extend effect engine with qt image effects (#249)

* - effects now can use qt image effects
- rainbow swirtl is now suitable for any led layout - including matrix

* fix rainbow effect

* effect: add radialGradient

* fix some js errors

* optimize code

* try fix travis test not working as expected

* fix default config files

* fix config

config/hyperion.config.json.default

@@ -96,7 +96,7 @@
 		"continuousOutput" : true
 	},
 
-	"grabber-v4l2" :
+	"grabberV4L2" :
 	[
 		{
 			"enable"   : false,
@@ -194,7 +194,7 @@
 
 	"webConfig" :
 	{
-		"enable"        : true,
+		"enable"        : true
 	},
 
 	"effects" :