make iOS 10.3 and Xcode 8.3 compatible (#345)

recompile SvgGh library with new code singature needed by iOS 10.3

vtm-ios/natives/SVGgh.framework/Headers/SVGContext.h

@@ -75,6 +75,17 @@ NS_ASSUME_NONNULL_BEGIN
 /*! @brief the value for 'currentColor' at this moment in the process of visiting a document
  */
 -(nullable UIColor*) currentColor;
+
+/*! @brief the value for 'opacity' at this moment in the process of visiting a document
+ */
+-(CGFloat) opacity;
+
+/*! @brief opacity is dependent (via inheritence) as you descend an SVG Document. This opacity is the place to keep track of updated opacity.
+ * @param the current opacity (defaults to 1.0)
+ */
+-(void) setOpacity:(CGFloat)opacity;
+
+
 /*! @brief the active language expected by the user like 'en' or 'sp' or 'zh'
  */
 -(nullable NSString*) isoLanguage;
@@ -89,7 +100,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 /*! @brief  Look through the CSS attributes for a given styling attribute.
  * @param attributeName the name of the attribute like 'line-width'
- * @param className the name of the CSS class like 'background' or some other arbitrary item
+ * @param listOfClasses the name of the CSS class like 'background' or some other arbitrary item
  * @param entityName the name of the entity like 'rect' or 'polyline'
  */
 -(nullable NSString*) attributeNamed:(NSString*)attributeName classes:(nullable NSArray<NSString*>*)listOfClasses entityName:(nullable NSString*)entityName;