Let setup.py compile_catalog process all language files

Two years ago the translation files have been split into several
files, separating the log messages of different log levels from each
other, like X.pot, X-log-warning.pot, X-log-info.pot, and so on.
However, the setup.py command `compile_catalogs`, that comes from the
babel package and compiles the corresponding .po files into .mo
files, only supported one file per python package.  This means that
during packaging `compile_catalogs` never compiled the X-log-*.po
files, so the corresponding translations were always missing.

Since babel 2.3 the domain can be set to a space separated list of
domains.  This change adds the the additional log level files to the
domain list.

The obsolete check that .po and .pot files are valid is removed from
tox.ini.

Change-Id: I1f0bfb181e2b84ac6dd0ce61881cd2cc4400bdcb
Closes-Bug: #1536226

setup.cfg

@@ -49,7 +49,7 @@ source-dir = doc/source
 
 [compile_catalog]
 directory = keystone/locale
-domain = keystone
+domain = keystone keystone-log-critical keystone-log-error keystone-log-info keystone-log-warning
 
 [update_catalog]
 domain = keystone

tox.ini

@@ -47,9 +47,6 @@ commands =
   # Run bash8 during pep8 runs to ensure violations are caught by
   # the check and gate queues
   bashate examples/pki/gen_pki.sh
-  # Check that .po and .pot files are valid.
-  bash -c "find keystone -type f -regex '.*\.pot?' -print0| \
-           xargs -0 -n 1 msgfmt --check-format -o /dev/null"
   # Run security linter
   bandit -r keystone -x tests