Fixed '--version' for trove processes/utilities

The trove processes (trove-manage, trove-conductor, trove-api, etc.)
returned an empty string when invoked with --version. They now return
the correct version string.

Change-Id: Ic14597e30928c753eae3090b401fbd66e042b93b
Closes-Bug: #1338767

trove/__init__.py

@@ -21,3 +21,15 @@
    :synopsis: Platform-As-A-Service Database Cloud
 .. moduleauthor:: Michael Basnight <mbasnight@gmail.com>
 """
+
+__all__ = ['__version__']
+
+import pbr.version
+
+version_info = pbr.version.VersionInfo('trove')
+# We have a circular import problem when we first run python setup.py sdist
+# It's harmless, so deflect it.
+try:
+    __version__ = version_info.version_string()
+except AttributeError:
+    __version__ = None

trove/common/cfg.py

@@ -15,6 +15,7 @@
 #    under the License.
 """Routines for configuring Trove."""
 
+import trove
 from oslo.config import cfg
 from trove.openstack.common import log as logging
 
@@ -445,4 +446,5 @@ def custom_parser(parsername, parser):
 def parse_args(argv, default_config_files=None):
     cfg.CONF(args=argv[1:],
              project='trove',
+             version=trove.__version__,
              default_config_files=default_config_files)