Provide creating real unique constraints for columns

Main issue is that we can't create unique constraint for columns, because
we are using soft deletion of entries (set `deleted` column to True).

The main idea is to use `deleted` columns to create unique constraint for
columns. For example (`col1`, `deleted`).

To make (`col1`, `deleted`) unique after entry deletion, we should assign the
value of `id` to `deleted` column.

Change type of `deleted` column from Boolean to table.id.type for all tables.

Change models.soft_delete() method to assign table.id instead of True to
`deleted` column.

Change query.soft_delete() method to assign literal_column("id") instead of True

Change in db.models all occurrences of Table.deleted == False =>
Table.deleted == correct_type (0 or "")

Value of `deleted` property of entries is used in public nova api. To keep API
as is, we should change XMLDictSerializer by converting the type of
`deleted` property to string representation of boolean.

Change db.api.model_query() method to make it work with different types
of `deleted` column.
If we are using as model that is not subclass of NovaBase we should set
parameter base_model as subclass of NovaBase that corresponds to model.

Change in db.api all occurrences of using model_query with model that is not
subclass of NovaBase.

blueprint db-unique-keys

Change-Id: Ie1f67f49a5d085e6371efb63fc23a1c8b25d9464
Bump the base rpc version of the network api to 1.7.

Change I2627e8b0f45c5c39bbbf1a4a12b448e1992fa4b4
bumped the RPC version of the API to 1.7
but did not bump the RPC version in the network
manager.

Change-Id: I1c719a1458ef5892e90aabee92a8b5e93cfa11c8
Merge "Bump the base rpc version of the network api to 1.7."
Don't pass the entire list of instances to compute

We don't need to pass the entire (potentially large) list of instances
down to the compute node. This will save potentially thousands of
bytes in the message.

Fixes bug 1103669

Change-Id: Ia90a19dffa90575a0f02191603ae9e96ca9258df
Merge "Don't pass the entire list of instances to compute"
Merge "Provide creating real unique constraints for columns"