remove VImage::scale()

it clashed with the VipsScale operator, see

https://github.com/jcupitt/libvips/pull/213

ChangeLog

@@ -1,5 +1,7 @@
 30/12/14 started 7.42.2
 - C++ required output params were broken, thanks Lovell
+- remove VImage::scale() to get scale from header, it clashed with the
+  VipsScale operator, thanks Lovell
 - allow c++ set enum from string
 - display param default and range in usage
 - better docs

cplusplus/include/vips/VImage8.h

@@ -323,18 +323,6 @@ public:
 		return( vips_image_get_filename( get_image() ) ); 
 	}
 
-	double 
-	scale()
-	{
-		return( vips_image_get_scale( get_image() ) ); 
-	}
-
-	double 
-	offset()
-	{
-		return( vips_image_get_offset( get_image() ) ); 
-	}
-
 	const void *
 	data()
 	{