Add i18n support

This patch adds i18n support to Higgins. We'd better use i18n
translator for all log messages generated from the beginning.

Change-Id: I8344f3a038792ad4703ecdbc955bbf5c73b0cd8f

higgins/common/i18n.py

@@ -0,0 +1,35 @@
+# Copyright 2014 IBM Corp.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# It's based on oslo.i18n usage in OpenStack Keystone project and
+# recommendations from http://docs.openstack.org/developer/oslo.i18n/usage.html
+
+import oslo_i18n
+
+
+_translators = oslo_i18n.TranslatorFactory(domain='higgins')
+
+# The primary translation function using the well-known name "_"
+_ = _translators.primary
+
+# Translators for log levels.
+#
+# The abbreviated names are meant to reflect the usual use of a short
+# name like '_'. The "L" is for "log" and the other letter comes from
+# the level.
+_LI = _translators.log_info
+_LW = _translators.log_warning
+_LE = _translators.log_error
+_LC = _translators.log_critical

requirements.txt

@@ -3,3 +3,4 @@
 # process, which may cause wedges in the gate later.
 
 pbr>=1.6 # Apache-2.0
+oslo.i18n>=2.1.0 # Apache-2.0