Refactor db.service_destroy and db.service_update methods

Remove session parameter from db.service_get method

Optimize db.service_destroy:
Was:
1 request with join to get service with compute_node
1 request to delete service
1(0) to delete compute_node
Now:
1 request (without join) to delete service
1 request to delete compute_node

Optimize db.service_update:
Remove unused join.

Fixes bug 1157442

blueprint db-session-cleanup

Change-Id: Ifcc8fdebfc95daec736464cbc9e16301116540aa
Update the network info when using quantum.

The network info cache in quantum was not updated with floating ips.
Also it wasn't updated properly updating the network info cache
during some operations that changed it. This adds floating ips and
updates the cache properly.

Fixes bug 1108975

Change-Id: I9e9c211d014f9671d724cded1fb9a74313c458b6
Merge "Update the network info when using quantum."
Merge "Refactor db.service_destroy and db.service_update methods"