Merge branch 'mg/verify-commit'

Add 'verify-commit' to be used in a way similar to 'verify-tag' is
used.  Further work on verifying the mergetags might be needed.

* mg/verify-commit:
  t7510: test verify-commit
  t7510: exit for loop with test result
  verify-commit: scriptable commit signature verification
  gpg-interface: provide access to the payload
  gpg-interface: provide clear helper for struct signature_check

git.c

@@ -478,6 +478,7 @@ static struct cmd_struct commands[] = {
 	{ "upload-archive", cmd_upload_archive },
 	{ "upload-archive--writer", cmd_upload_archive_writer },
 	{ "var", cmd_var, RUN_SETUP_GENTLY },
+	{ "verify-commit", cmd_verify_commit, RUN_SETUP },
 	{ "verify-pack", cmd_verify_pack },
 	{ "verify-tag", cmd_verify_tag, RUN_SETUP },
 	{ "version", cmd_version },