add note on tiff autorot

TODO

@@ -1,3 +1,34 @@
+- support orientation tag in tiff images
+
+  see
+
+  	http://www.awaresystems.be/imaging/tiff/tifftags/orientation.html
+
+  seems to be the same values used for exif
+
+  jpg uses "exif-ifd0-Orientation", see conversion/autorot.c
+
+  instead, standardize on "orientation" and give it an int value
+
+  jpg load and save need to use this in preference to the exif value
+
+  tiff load and save need to set and recover this value
+
+  tiff load needs an autorot flag 
+
+  	don't touch parse_header()
+
+	on header-only read, just swap width/height and delete the tag
+
+	on full image read, use read_jpeg_rotate(), broken out into a separate
+	func
+
+  see https://github.com/jcupitt/libvips/issues/243
+
+
+
+
+
 - why can't we do
 
 	im = Vips.Image.new_from_file(sys.argv[1], access = "sequential")