Move network call from compute API to the manager

reboot gets network info from the network manager in the API only to pass
it to the manager.  This causes an un-needed delay on the API call.  It
also causes issues with cells, as with cells you should query the network
service close to that cell.

Fixes bug 1098741

Change-Id: If6badc007ad812e5539a3738911011685cf9df35
More HostAPI() cleanup for cells.

This patch contains further changes needed to support HostAPI() with
cells.  This moves the formatting of hosts API extension responses back
to the extension itself.  Methods for getting service entries have been
added to HostAPI() that can be overriden in a subclass for cells.

Also contains a performance improvement for 'show' in hosts extension.

Change-Id: Ifd8b68ff8d7495f537dff5e01bd3df75c6c5930a
Populate service list with availability zone and correct unit test

Availability zone was removed from the service object and is now added
via a separate call to availabilty_zones.set_availability_zones. Fix
the fake_services_list structure in test_services to reflect that
availability zone is no longer returned but added separately based
on the topic.

NOTE: original fix was reverted, combining unit test fix and original
change here.

bug 1099399
Change-Id: Ic9675a88c2c229d6feb20f5b934458e10c17684f
Merge "Move network call from compute API to the manager"
Merge "Populate service list with availability zone and correct unit test"
Merge "More HostAPI() cleanup for cells."