gpg: Add a new test.
* g10/Makefile.am (EXTRA_DIST): Add t-stutter-data.asc. (module_tests): Add t-stutter. (t_stutter_SOURCES): New variable. (t_stutter_LDADD): New variable.
Add a test to check that the Mister and Zuccerato attack described in
"An Attack on CFB Mode Encryption As Used by OpenPGP" works.
- Signed-off-by: Neal H. Walfield <neal@g10code.com>