Fixed constructors

src/Canvas.cc

@@ -13,6 +13,8 @@
 #include <node_buffer.h>
 #include <node_version.h>
 
+Persistent<FunctionTemplate> Canvas::constructor;
+
 /*
  * Buffer data pointer access.
  */

src/CanvasGradient.cc

@@ -8,6 +8,8 @@
 #include "Canvas.h"
 #include "CanvasGradient.h"
 
+Persistent<FunctionTemplate> Gradient::constructor;
+
 /*
  * Initialize CanvasGradient.
  */

src/CanvasRenderingContext2d.cc

@@ -14,6 +14,8 @@
 #include "CanvasRenderingContext2d.h"
 #include "CanvasGradient.h"
 
+Persistent<FunctionTemplate> Context2d::constructor;
+
 /*
  * Set RGBA.
  */

src/Image.cc

@@ -10,6 +10,8 @@
 #include <stdlib.h>
 #include <string.h>
 
+Persistent<FunctionTemplate> Image::constructor;
+
 /*
  * Initialize Image.
  */

src/ImageData.cc

@@ -7,6 +7,8 @@
 
 #include "ImageData.h"
 
+Persistent<FunctionTemplate> ImageData::constructor;
+
 /*
  * Initialize ImageData.
  */

src/PixelArray.cc

@@ -9,6 +9,8 @@
 #include <stdlib.h>
 #include <string.h>
 
+Persistent<FunctionTemplate> PixelArray::constructor;
+
 /*
  * Initialize PixelArray.
  */