Port to graduated library oslo.i18n

log_handler is not used any more by Ceilometer project, but still
listed on openstack-common.conf, this patch fixes it.

Note: oslo-incubator.timeutils is not used by oslo-incubator modules
any more after we do code sync, this patch removes it too.

gettextutils has graduated from oslo-incubator, we should port our
project to use oslo.i18n. To use oslo.i18n conveniently, this patch
introduces a helper module ceilometer.i18n, which is stolen from Nova.

Note: gettextutils.install is deprecated, see:
http://docs.openstack.org/developer/oslo.i18n/usage.html#creating-an-integration-module
Note: _ is removed from builtins in tox.ini since we're not using
install any more.

Change-Id: I829f9faf97c825422b395bf9c01ae5c17c86d9fb
Closes-Bug: #1389546

ceilometer/service.py

@@ -21,10 +21,10 @@ import socket
 import sys
 
 from oslo.config import cfg
+from oslo import i18n
 
+from ceilometer.i18n import _
 from ceilometer import messaging
-from ceilometer.openstack.common import gettextutils
-from ceilometer.openstack.common.gettextutils import _
 from ceilometer.openstack.common import log
 from ceilometer import utils
 
@@ -113,8 +113,7 @@ def get_workers(name):
 
 
 def prepare_service(argv=None):
-    gettextutils.install('ceilometer')
-    gettextutils.enable_lazy()
+    i18n.enable_lazy()
     log_levels = (cfg.CONF.default_log_levels +
                   ['stevedore=INFO', 'keystoneclient=INFO'])
     cfg.set_defaults(log.log_opts,