Merge branch 'st/verify-tag'

"git tag" and "git verify-tag" learned to put GPG verification
status in their "--format=<placeholders>" output format.

* st/verify-tag:
  t/t7004-tag: Add --format specifier tests
  t/t7030-verify-tag: Add --format specifier tests
  builtin/tag: add --format argument for tag -v
  builtin/verify-tag: add --format to verify-tag
  ref-filter: add function to print single ref_array_item
  gpg-interface, tag: add GPG_VERIFY_OMIT_STATUS flag

ref-filter.h

@@ -109,4 +109,11 @@ struct ref_sorting *ref_default_sorting(void);
 /*  Function to parse --merged and --no-merged options */
 int parse_opt_merge_filter(const struct option *opt, const char *arg, int unset);
 
+/*
+ * Print a single ref, outside of any ref-filter. Note that the
+ * name must be a fully qualified refname.
+ */
+void pretty_print_ref(const char *name, const unsigned char *sha1,
+		const char *format);
+
 #endif /*  REF_FILTER_H  */