Move configuration to new YGConfig and pass them down to CalculateLayout

Summary:
Move configuration to new ```YGConfig``` and pass them down to CalculateLayout. See #418 .

Adds ```YGConfigNew()``` + ```YGConfigFree```, and changed ```YGSetExperimentalFeatureEnabled``` to use the config.

New function for calculation is ```YGNodeCalculateLayoutWithConfig```.
Closes https://github.com/facebook/yoga/pull/432

Reviewed By: astreet

Differential Revision: D4611359

Pulled By: emilsjolander

fbshipit-source-id: a1332f0e1b21cec02129dd021ee57408449e10b0

javascript/sources/Node.hh

@@ -18,12 +18,14 @@
 #include "./Layout.hh"
 #include "./Size.hh"
 #include "./Value.hh"
+#include "./Config.hh"
 
 class Node {
 
  public:
 
     static Node * create(void);
+    static Node * create(Config * config);
     static void destroy(Node * node);
 
  public: