Restrict '-v' change to log --short only.
* bzrlib/tests/blackbox/test_log.py:
(TestLog.test_log_long_verbose,
TestLog.test_log_long_verbose_verbose): Update tests to reflect
--long ignoring verbosity level.
* bzrlib/log.py:
(LongLogFormatter.log_revision): Ignore verbosity level to
preserve compatibility.