Fixes #27

Implements basic segmented networking by providing a new "segment_id"
column. This column is used for lookups when assigning IP addresses out
of "shared" networks. If one attempts to create a port on a shared
network without providing the segment_id, ambiguity exceptions are
raised. Additionally, extends subnets to allow a segment_id to be passed
when the subnet is created.

quark/api/extensions/subnets_quark.py

@@ -19,6 +19,7 @@ from neutron.api import extensions
 
 EXTENDED_ATTRIBUTES_2_0 = {
     'subnets': {
+        "segment_id": {"allow_post": True, "default": False},
         "enable_dhcp": {'allow_post': False, 'allow_put': False,
                         'default': False,
                         'is_visible': True},