Base maximum output dimensions on limitation of format

src/common.h

@@ -184,6 +184,11 @@ namespace sharp {
   */
   void SetDensity(VImage image, const int density);
 
+  /*
+    Check the proposed format supports the current dimensions.
+  */
+  void AssertImageTypeDimensions(VImage image, ImageType const imageType);
+
   /*
     Called when a Buffer undergoes GC, required to support mixed runtime libraries in Windows
   */