Update clang-format rules

Summary: Spent a couple hours customizing the clang-format rules to better match the desired code style.

Reviewed By: IanChilds

Differential Revision: D3714510

fbshipit-source-id: f6d0436346416aab023aacbedd70ea189e583e8d

CSSLayout/CSSLayout-internal.h

@@ -90,10 +90,10 @@ typedef struct CSSNode {
   struct CSSNode *nextChild;
 
   CSSSize (*measure)(void *context,
-      float width,
-      CSSMeasureMode widthMode,
-      float height,
-      CSSMeasureMode heightMode);
+                     float width,
+                     CSSMeasureMode widthMode,
+                     float height,
+                     CSSMeasureMode heightMode);
   void (*print)(void *context);
   void *context;
 } CSSNode;