1115715 - syslog handler works with string formatting tokens in stack traces.

https://bugzilla.redhat.com/show_bug.cgi?id=1115715

Also added (1) test for unrelated missing coverage.
```
[jortel@localhost unit]$ nosetests --with-coverage --cover-package=pulp.server.logs server/test_logs.py
.......................
Name               Stmts   Miss  Cover   Missing
------------------------------------------------
pulp.server.logs      71      0   100%   
----------------------------------------------------------------------
Ran 23 tests in 0.032s

OK
```