nova: use the correct notification driver

Nova now uses oslo.messaging and not the Oslo RPC code anymore,
therefore the new driver should be used instead.

Change-Id: I3533975ad38ff99bee6cfaa5332843444650f61f
Fix misspellings in devstack

Fix misspellings detected by:
 * pip install misspellings
 * git ls-files | grep -v locale | misspellings -f -

Change-Id: I19726438d15cd27b813504aac530e7e53c4def12
Closes-Bug: #1257295
Merge "nova: use the correct notification driver"
Merge "Fix misspellings in devstack"
Merge branch 'master' of https://github.com/openstack-dev/devstack