add missing flags

sine we now have proper flags support

Author: jcupitt

lib/vips/foreign_keep.rb

@@ -0,0 +1,14 @@
+module Vips
+  # Savers can be given a set of metadata items to keep.
+  #
+  # *   `:none` remove all metadata
+  # *   `:exif` keep EXIF metadata
+  # *   `:xmp` keep XMP metadata
+  # *   `:iptc` keep IPTC metadata
+  # *   `:icc` keep ICC profiles
+  # *   `:other` keep other metadata
+
+  class ForeignKeep < Symbol
+  end
+end
+

lib/vips/foreign_png_filter.rb

@@ -0,0 +1,16 @@
+module Vips
+  # The set of filters for PNG save. See http://www.w3.org/TR/PNG-Filters.html
+  #
+  # *   `:none` no filtering
+  # *   `:sub` difference to the left
+  # *   `:up` difference up
+  # *   `:avg` average of left and up
+  # *   `:paeth` pick best neighbor predictor automatically
+  # *   `:all` adaptive
+
+  class ForeignPngFilter < Symbol
+  end
+end
+
+
+