Don't use a query for watch_rule_get()

When getting a database record by ID, it is much more efficient to get() it
directly than to perform a query or the database to obtain the ID (again)
and then get it.

Change-Id: I89b46d698c033e54ee9a50172ccad3eb3833cb1e
Allowing to pass network name to router gateway

This patch allows to pass newtork name instead of network id to create router
gateway. It is really useful feature because often router has gateway as public
network. It is easy to pass the name because id will change after deleting the
network and creating it again.

Change-Id: I5768408b86b509ecfd117f17b10db06af82369d8
Merge "Don't use a query for watch_rule_get()"
Merge "Allowing to pass network name to router gateway"