Add bulk create/destroy functionality to FloatingIP

This adds bulk create and destroy functionality to the FloatingIP
object, which in turn requires that the DB API return the list of
IPs that it created.

This also fixes a bug in the load routine for FloatingIP, which
would previously try to load a FixedIP object with id=None,
which doesn't make sense.

Related to blueprint compute-manager-objects-juno

Change-Id: Ie3c7a5e672fcdb3e0df3d0e46b905b237dcfa182
Completely object-ify the floating_ips_bulk V2 extension

This converts the floating_ips_bulk APIv2 extension from using
direct DB access to using the FloatingIP object.

Related to blueprint compute-manager-objects-juno

Change-Id: I5fa7637b5eb06a9be51d7638701d98e3e033d68d
Move the fixed_ips APIv2 extension to use objects

This converts the fixed_ips extension to use the FixedIP object
instead of direct database access.

Related to blueprint compute-manager-objects-juno

Change-Id: I21afae063a360c1c36a417f0455e213b7236b541
Object-ify server_password APIv2 extension

This makes the server_password extension use the Instance object
instead of direct database access.

Related to blueprint compute-manager-objects-juno

Change-Id: I54f7762d14868278ef72589a8c6e3fc80c0e48c8
Object-ify server_password APIv3 extension

This makes the server_password APIv3 extension use the Instance object
instead of direct database access.

Related to blueprint compute-manager-objects-juno

Change-Id: I960840e8261bacd4a9c99934f02342861e53bc74
Removes the use of mutables as default args

Passing mutable objects as default args is a known Python pitfall.
We'd better avoid this. This commit changes mutable default args with
None, then use 'arg = arg or {}', 'arg = arg or []'. For unit code which
doesn't use the args , just set with None. This commit also adds hacking
check.

Closes-Bug: #1327473
Change-Id: I5a8492bf8ffef8e000b13b6bdfaef1968b96f816
Merge "Removes the use of mutables as default args"
Merge "Add bulk create/destroy functionality to FloatingIP"
Merge "Completely object-ify the floating_ips_bulk V2 extension"
Merge "Move the fixed_ips APIv2 extension to use objects"
Merge "Object-ify server_password APIv2 extension"
Merge "Object-ify server_password APIv3 extension"