Remove deprecated config option names: Juno Edition

Just like the beginning of every other release, remove the deprecated
config option aliases that were marked as deprecated in Icehouse.

Equivalent Icehouse patch: I64548e40f6cea42275a6f0f3ebdc0c4cd9324804

DocImpact: Configurations that were deprecated in the Icehouse release are not
recognized in Juno.

Change-Id: I346ee0248c03e60716bd7dc4a5ee4493610867cb
Make metadata password routines use Instance object

This replaces existing uses of raw conductor apis for get_by_uuid()
and instance_update() with objects.

Related to blueprint compute-manager-objects-juno

Change-Id: I63cf0ac6636e17f2bfcd9d6a859d9ed8612a56e1
Deprecate instance_get_by_uuid() from conductor

Aside from a few trivial-to-fix places in the unit tests, the
conductor instance_get_by_uuid() method is no longer used. This
deprecates it and cleans up the few places that were trivially
touching it.

Related to blueprint compute-manager-objects-juno

Change-Id: Iab48856c0432af0b9483e9868c2e235de75fdd51
Merge "Make metadata password routines use Instance object"
Merge "Deprecate instance_get_by_uuid() from conductor"
Merge "Remove deprecated config option names: Juno Edition"