Cope better with out of sync bm data.

The baremetal hypervisor tracks references to instances which are
deleted asynchronously from the commit to the nova bm. As such, its a
normal but rare condition for a bare metal node to refer to a deleted
(and even garbage collected) nova instance. We should treat such
instances are deleted rather than erroring on any call through
list_instances(), permitting starting new instances and listing
instances to work - fixing bug: 1096722.

Pathologically, the database may suffer permanent skew, which means we
need a way to fix it (and thats tracked as a separate bug).

Change-Id: Ic21ff66b1fc0ad64bb5feff26291873b96d20e4e
fix N402 for nova/db

fixes N402 (single line docstring must end in a period) for nova/db

Change-Id: I31779cbf83fa77c7cc382cce1667812f8cdecd61
fix N402 for nova/c*

fix N402 (single line docstring comments should end in a period)
for nova/cells, nova/compute, and nova/conductor

Change-Id: Ia2d4e64f4dde346a26aeba8cf10dd2000585caa0
fix N402 for rest of nova

fix N402 (single line docstrings should end in a period) for
rest of nova files

Change-Id: I57d0d9ab01345dd83e544e476d79d2c2ca68ee51
fix N402 for nova-manage

fix N402 (docstrings should end in a period) for nova-manage

Change-Id: Ia07796117fb9fce6c098a58aa86a6b47c6f7eda0
fix N402 on tools/

fix N402 (single line docstrings should end in a period)

Change-Id: I2086dfb33a6efeb6ef6edc6a326182b6deda2527
Merge "Cope better with out of sync bm data."
Merge "fix N402 for nova/db"
Merge "fix N402 for nova/c*"
Merge "fix N402 for rest of nova"
Merge "fix N402 for nova-manage"
Merge "fix N402 on tools/"