Updates latest OSLO changes

Change-Id: Ief4a24a620b798bf8ece393e90c292c8121ae280
Add l3 db migration for plugins which did not support in folsom

Bug 1153585

Several plugins added l3 support in the grizzly release. This means that
when upgrading from the folsom data model, the relevant data model changes
should be applied.
In order to do so this patch refactors the initial migration in order
to be able to reuse the upgrade_l3 and downgrade_l3 routines.

Change-Id: I876f6d637665e10fb09d2084bb8a545ce469fbf3
Fix detection of deleted networks in DHCP agent.

The DHCP-agent uses an in-memory networks cache to find out which networks must
be deleted and which ones must be updated. In a case of agent restart the networks
cache is empty and it's not possible to cleanup DHCP-processes serving networks
which were deleted while the DHCP-agent was down. The proposed fix fills the networks
cache when the agent starts using a list of networks which have existing config files.

Fixes: bug #1135948
Change-Id: I27758389755cd19bca9fdbeda9cc1a123370f527
Merge "Updates latest OSLO changes"
Adds Grizzly migration revision

fixes bug 1154255

This change adds a no-op migration called grizzly.  Deployers can reference
the symbolic name when updating their databases from Folsom.

Change-Id: I442586f1efdb52b7ec8b318077ace52f570b3ae4
Merge "Adds Grizzly migration revision"
Merge "Fix detection of deleted networks in DHCP agent."
Merge "Add l3 db migration for plugins which did not support in folsom"