* photoid.h, photoid.c (parse_image_header, image_type_to_string): Useful

functions to return data about an image.

* packet.h, parse-packet.c (make_attribute_uidname,
parse_attribute_subpkts, parse_attribute), photoid.h, photoid.c
(show_photos): Handle multiple images in a single attribute packet.

* main.h, misc.c (pct_expando), sign.c (mk_notation_and_policy), photoid.c
(show_photos): Simpler expando code that does not require using
compile-time string sizes.  Call image_type_to_string to get image strings
(i.e. "jpg", "image/jpeg").  Change all callers.

* keyedit.c (menu_showphoto), keylist.c (list_keyblock_print): Allow
viewing multiple images within a single attribute packet.

* gpgv.c: Various stubs for link happiness.

g10/packet.h

@@ -148,15 +148,11 @@ typedef struct {
     MPI  data[PUBKEY_MAX_NSIG];
 } PKT_signature;
 
-typedef enum
-{
-  ATTRIB_UNKNOWN,
-  ATTRIB_JPEG
-} attribtype_t;
+#define ATTRIB_IMAGE 1
 
 /* This is the cooked form of attributes */
 struct user_attribute {
-  attribtype_t type;
+  byte type;
   const byte *data;
   unsigned long len;
 };