avocado: Rename avocado.app.traceback log stream to avocado.app.debug

Lets share this log with all debug info in avocado not enabled by default.
Signed-off-by: NLukáš Doktor <ldoktor@redhat.com>

avocado/core/job.py

@@ -412,7 +412,7 @@ class Job(object):
         try:
             test_suite = self._make_test_suite(self.urls)
         except loader.LoaderError, details:
-            stacktrace.log_exc_info(sys.exc_info(), 'avocado.app.tracebacks')
+            stacktrace.log_exc_info(sys.exc_info(), 'avocado.app.debug')
             self._remove_job_results()
             raise exceptions.OptionValidationError(details)
         if not test_suite:

avocado/core/loader.py

@@ -210,8 +210,7 @@ class TestLoaderProxy(object):
                                    "%s" % (plugin, details),
                                    'avocado.app.exceptions')
             # FIXME: Introduce avocado.traceback logger and use here
-            stacktrace.log_exc_info(sys.exc_info(),
-                                    'avocado.app.tracebacks')
+            stacktrace.log_exc_info(sys.exc_info(), 'avocado.app.debug')
         tests = []
         unhandled_urls = []
         if not urls: