Enable lazy translation

This change makes it so that if the user makes a request with an
Accept-Language header and the response is an error where the
message is translatable, then the message will be translated to
the requested language (or the most appropriate language
available).

completes bp user-locale-api

Change-Id: I5b0b02e0459a6a444baa12f8722adb829b7e152b

bin/keystone-all

@@ -40,7 +40,7 @@ from keystone.openstack.common import gettextutils
 # NOTE(blk-u):
 # gettextutils.install() must run to set _ before importing any modules that
 # contain static translated strings.
-gettextutils.install('keystone')
+gettextutils.install('keystone', lazy=True)
 
 from keystone.common import dependency
 from keystone.common import environment

bin/keystone-manage

@@ -32,7 +32,7 @@ from keystone.openstack.common import gettextutils
 
 # NOTE(blk-u): gettextutils.install() must run to set _ before importing any
 # modules that contain static translated strings.
-gettextutils.install('keystone')
+gettextutils.install('keystone', lazy=True)
 
 from keystone import cli
 from keystone.common import environment

httpd/keystone.py

@@ -24,7 +24,7 @@ from keystone.openstack.common import gettextutils
 # NOTE(blk-u):
 # gettextutils.install() must run to set _ before importing any modules that
 # contain static translated strings.
-gettextutils.install('keystone')
+gettextutils.install('keystone', lazy=True)
 
 from keystone.common import dependency
 from keystone.common import environment

keystone/contrib/kds/cli/api.py

@@ -21,7 +21,7 @@ from wsgiref import simple_server
 from keystone.openstack.common import gettextutils
 
 PROJECT = 'kds'
-gettextutils.install(PROJECT)
+gettextutils.install(PROJECT, lazy=True)
 
 from keystone.contrib.kds.api import app
 from keystone.contrib.kds.common import service