Added property display: flex and none

Summary:
Fix #241 and successor for #302

Added new property ```display``` with ```YGDisplayFlex``` and ```YGDisplayNone```. Allows to hide nodes from the layout without the need to remove it from the DOM.
Closes https://github.com/facebook/yoga/pull/369

Reviewed By: astreet

Differential Revision: D4501141

Pulled By: emilsjolander

fbshipit-source-id: 0dfeee381f6d1e4bbba81926126b83dd7abab9d6

yoga/Yoga.h

@@ -157,6 +157,7 @@ YG_NODE_STYLE_PROPERTY(YGAlign, AlignSelf, alignSelf);
 YG_NODE_STYLE_PROPERTY(YGPositionType, PositionType, positionType);
 YG_NODE_STYLE_PROPERTY(YGWrap, FlexWrap, flexWrap);
 YG_NODE_STYLE_PROPERTY(YGOverflow, Overflow, overflow);
+YG_NODE_STYLE_PROPERTY(YGDisplay, Display, display);
 
 WIN_EXPORT void YGNodeStyleSetFlex(const YGNodeRef node, const float flex);
 YG_NODE_STYLE_PROPERTY(float, FlexGrow, flexGrow);