Open Juno development

Bump preversion to 2014.2 to formally open Juno development.
The Icehouse release branch (milestone-proposed) will be cut
from the last commit before this one.

Change-Id: I0af1ee46e65149eb19731491242ddc2fdccd7a2e
Invoke _process_l3_create within plugin session

_process_l3_create should be invoked with a plugin session, else
externalnetworks table is not populated for networks with
router:external=True. Added the missing plugin session.

Change-Id: I09c49dea9474f91a70aef829c1596fbb9089d6cf
Closes-Bug: #1299946
BigSwitch: Semaphore on port status update

Adds a semaphore to the _set_port_status
function used by the Big Switch ML2 driver and
plugin. Without it, the async threads are
susceptible to deadlocking and causing the
known eventlet/mysql timeout exception.

Closes-Bug: #1300607
Change-Id: Ie89213a0bef37f9e7a30945df39c0f1b87a33b82
Merge "Invoke _process_l3_create within plugin session"
Merge "Open Juno development"