Corrects a flaw in the treatment of swift endpoints

When keystone has a registered swift endpoint of which the url does not start
with '/v1', the object-store pollster is not able to use it correctly.
This commit fixes it's behaviour to provide more flexibility in endpoint urls.

Change-Id: I579b1cf450f16853ac49f1d248a64a179e6443d9
Closes-Bug: #1325591
Fix list of modules not included in auto-gen docs

The variable for excluding modules should be a sequence of strings.
Turn the current value from a string to a tuple so documentation
for our source is generated.

The errors and warnings were fixed in the docstrings in the source code
otherwise the doc generation would fail.

The following files were excluded from the doc build because of
non-existing imports:

 'ceilometer.compute.nova_notifier'
    http://bit.ly/remove-nova-notifier-bp
 'ceilometer.openstack.common.db.sqlalchemy.session'
    https://review.openstack.org/#/c/97850/
 'ceilometer.openstack.common.middleware.audit'
 'ceilometer.openstack.common.middleware.notifier'
    https://bugs.launchpad.net/ceilometer/+bug/1327084
 'ceilometer.openstack.common.log_handler'
    https://bugs.launchpad.net/ceilometer/+bug/1327076

These failed imports are registered in one blueprint and two bug reports.

Change-Id: If0bc1c8fc96ba513bbeb90d5257e40b7621a8473
Fix messaging.get_transport caching

If some case get_transport can return a cached transport
even cache=False

This change fixes it and also adds some unit tests for this method

Change-Id: If87cf60d0a25a84dd05f1b84c35f1bcbfeb69b75
Merge "Fix list of modules not included in auto-gen docs"
Merge "Corrects a flaw in the treatment of swift endpoints"
Merge "Fix messaging.get_transport caching"