plugin/nec: Make sure resources on OFC is globally unique.

V3 and V4 of NEC ProgrammableFlow controller (PFC) generates a network ID
unique inside a tenant. On the other hand, ID mapping table in NEC plugin
expects ID on OFC is globally unique. As a result creation of a network
will fail. To fix it, quantum network ID is passed as ID on OFC.
The same issue happens in port creation too.

In Grizzly this bug was fixed in another way (to support shared network),
but this change is quite big and it cannot be backported.
The minimum way to fix this bug is to specify OFC network ID from Quantum.

Since V3 of PFC does not return network/port ID in the response when ID is
passed in the request, create_network/port is changed to return an ID
passed to the controller instead of extracting ID from the response.

Fixes bug #1127664

Change-Id: Iad1961ee2469b547598e87e63a4a3dc4ac9c6e97
plugin/nec: Drop description field from PFC create_tenant

Some version of PFC, one of OpenFlow controllers supported in NEC
plugin, does not accept "description" field in create_tenant().

Removes update_tenant() in pfc.py since it is not used anywhere.

Fixes bug #1166076

Change-Id: I817bb67465ff47df43ad2ea866e40c4413f29cbb
plugin/nec: Ensure ID on PFC is up to 31 chars

Some version of NEC ProgrammableFlow OpenFlow controller, one of
the OpenFlow controllers (OFCs), accepts the string up to 31 chars
as a network ID. NEC plugin now uses Quantum UUID as ID on OFC,
so this leads to failure on network creation. This commit changes
the plugin to generate a 31-char ID on OFC to keep its uniqueness.
The same thing can be said to port ID.

Similarly, the description field must be a string up to 127 chars
and consist of [A-Za-z0-9_] characters. This change also fixes it.

Bug #1166077

Change-Id: I0a879f5158a6ac0ce332e3698d42dd38d4283a60
Final versioning for 2012.2.4

Change-Id: Ic9ee9a7336c8f5f64ad4700c0322653e331c10bb
Bump version to 2012.2.5

Change-Id: Ibf237525fc86d5ba2129620f58d574685a713782