Fail a test if time.sleep called for no reason

If a mild error screws something up in task manager, an entire class
of tests will continue polling using GET requests until they hit their
rate limit, destroying any attempt to parse the test output to see
what is wrong. This pull request fixes that.

Change-Id: I7c00a174dfb7970357ee2bd71550983d68e0e8ae
Closes-Bug: 1315518
Corrects the class name "ExtensionManager"

Corrects ExtensionManager to extensions.ExtensionManager which was
earlier written without the package name.

There were no errors encountered as first condition of the condition set
always evaluated True.

Change-Id: I1fd4016105a99a7baaad6d2613b0e709a09aeeb2
Closes-Bug: #1323400
Clean up openstack-common.conf

The issues are detected by new change about update.py
in I68c0108304be8a315bcefe939c22019caab9bc98. This patch
doesn't depend the oslo-incubator patch.
 * remove unused module config
 * add missing module loopingcall and remove module
   cfg in openstack-common.conf
 * sort the modules in openstack-common.conf

Closes-Bug: #1323622
Change-Id: I10cca7386ea8e586f7e35a2f0e5b3c5c14906d7e
Merge "Fail a test if time.sleep called for no reason"
Merge "Corrects the class name "ExtensionManager""
Merge "Clean up openstack-common.conf"