Fix for multiple misspelled words

In Nova code, few misspelled words have been found.
The misspellings python library has been used to scan
all nova code and find misspelled words.
This commit fixes all misspelled words found with this library.

Change-Id: I5919dddbbe812d8d32ecd8b249c1312249cd2a66
Closes-Bug: 1323730
Refactor test_rescue_unrescue into compute api/manager unit tests

As part of converting the rescue/unrescue compute API flows to using
objects, i.e. dot notation for accessing attributes on the instance
object and updating the database via instance.save() rather than
compute_api.update, we want to move some of the integration-style tests
found in test_compute.py to test_compute_api.py and test_compute_mgr.py.

This is to help with the conversion so we don't have to use exotic stubs
in the cells API flows to make integration tests work.

This change is mainly concerned with moving test_rescue_unrescue out of
test_compute.py and into the api/manager specific test modules and then
later changes will build on top of the new tests.

Part of blueprint compute-manager-objects-juno

Change-Id: I2a9b1c6b5a1f41272e26c20de134a2a8b71c88f3
Treat instance objects as objects in rescue API flow

The compute API and manager are getting instance objects now but
treating them like primitive dicts still in several places, so this
cleans that up.

Also adds the instance to the warning log message in _get_rescue_image
since (a) I'm already in there and (b) it adds context for the message,
which is useful.

Cleans up the related tests so they are using objects as well to verify
the changes to compute api/manager are correct.

Part of blueprint compute-manager-objects-juno

Change-Id: Ibe4473fc08fd68676aaa1e1c9ba69161fc5f527e
Treat instance objects as objects in unrescue API flow

The compute API and manager are getting instance objects now but
treating them like primitive dicts still in several places, so this
cleans that up.

Cleans up the related tests so they are using objects as well to verify
the changes to compute api/manager are correct.

Part of blueprint compute-manager-objects-juno

Change-Id: I81fa858a821a2137fce5970905b9b1c71c95304b
Merge "Refactor test_rescue_unrescue into compute api/manager unit tests"
Merge "Treat instance objects as objects in rescue API flow"
Merge "Treat instance objects as objects in unrescue API flow"
Merge "Fix for multiple misspelled words"