Move network and port locks to separate locks

* Because any plugin call can (in theory) be called from any other
  plugin call, each resource type needs its own lock to avoid
  deadlocks

Change-Id: Ia910aa8420f110d56140078e2502d86fc9a9eb4c
Signed-off-by: Joe Mills <joe@midokura.com>
(cherry picked from commit 2798517eff847ad5d9decbb5727dddac5242fbd4)