GUI: Support styles in xml to reduce xml file size

Also allow sliders to have their own text label instead of
requiring a whole separate text object for the label in the xml.

Change-Id: I6e314efb4bb454d496555ff7e003d743063a1308
diff --git a/gui/action.cpp b/gui/action.cpp
index aa81dff..f9de4e9 100644
--- a/gui/action.cpp
+++ b/gui/action.cpp
@@ -226,9 +226,9 @@
 	}
 
 	// First, get the action
-	actions = node->first_node("actions");
-	if (actions)	child = actions->first_node("action");
-	else			child = node->first_node("action");
+	actions = FindNode(node, "actions");
+	if (actions)	child = FindNode(actions, "action");
+	else			child = FindNode(node, "action");
 
 	if (!child) return;
 
@@ -247,7 +247,7 @@
 	}
 
 	// Now, let's get either the key or region
-	child = node->first_node("touch");
+	child = FindNode(node, "touch");
 	if (child)
 	{
 		attr = child->first_attribute("key");