refactor Use and Defs element with native code support(iOS)

ios/RNSVGNode.h

@@ -11,21 +11,22 @@
 #import "RNSVGSvgView.h"
 
 /**
- * RNSVG nodes are implemented as empty UIViews but this is just an implementation detail to fit
- * into the existing view management. They should also be shadow views and painted on a background
- * thread.
+ * RNSVG nodes are implemented as base UIViews. They should be implementation for all basic
+ ＊interfaces for all non-defination nodes.
  */
 
 @interface RNSVGNode : UIView
 
-@property (nonatomic, assign) CGRect rect;
+@property (nonatomic, strong) NSString *name;
 @property (nonatomic, assign) CGFloat opacity;
 @property (nonatomic, assign) RNSVGCGFCRule clipRule;
 @property (nonatomic, assign) CGPathRef clipPath; // convert clipPath="M0,0 L0,10 L10,10z" into path
 @property (nonatomic, strong) NSString *clipPathRef; // use clipPath="url(#clip)" as ClipPath
 @property (nonatomic, assign) BOOL responsible;
 
+
 - (void)invalidate;
+
 - (void)renderTo:(CGContextRef)context;
 
 /**
@@ -36,20 +37,41 @@
 - (void)renderLayerTo:(CGContextRef)context;
 
 /**
- * clip node by clipPath or clipPathId.
+ * clip node by clipPath or clipPathRef.
  */
 - (void)clip:(CGContextRef)context;
 
+/**
+ * get clip path for current node.
+ */
 - (CGPathRef)getClipPath;
 
 /**
  * getPath will return the path inside node as a ClipPath.
  */
-- (CGPathRef)getPath: (CGContextRef) context;
+- (CGPathRef)getPath:(CGContextRef) context;
 
 
+/**
+ * run hitTest
+ */
 - (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event;
 
 - (RNSVGSvgView *)getSvgView;
 
+/**
+ * save element`s defination into svg element.
+ */
+- (void)saveDefination:(CGContextRef)context;
+
+/**
+ * remove element`s defination from svg element.
+ */
+- (void)removeDefination;
+
+/**
+ * merge owned properties into target element`s properties
+ */
+- (void)mergeProperties:(__kindof RNSVGNode *)target;
+
 @end