added cookies for rule installs and send_rem_msg flag in runtime/backend/pox_client
rule diffing to explicitly create to_add, to_delete, to_stay lists. (Work in progress commit -- code **wont** work in current state)
bucket state book-keeping under classifier update, and corresponding match data structure changes. (work in progress commit)
partially added logic for querying only rules which already existed when a new bucket is created
handling flow stats issues for rules already on switches for new buckets
refactor existing rule stats queries and those on user behalf
handling existing rules in handle_flow_stats_reply
added flow removed support in backend and pox_client (work in progress)
adding priority to bucket.matches structure (work in progress)
flow removed accounting and bookkeeping in runtime and countbucket objects
basic flow modify functionality with OFPFC_MODIFY_STRICT in pox_client & backend
first cut of rule install function that is completely diff based
pipeline for diff lists-based rule installation coming together
installation pipeline code fully with classifier difference lists
lots of bug fixes; simple static query policies tested to work with new code
bug fixes; diagnostic prints. WIP: dynamic policy queries work but stats requests are delayed
merged master into dynamic queries branch; conflicts fixed
bug fixes after merge; slow stats_reply problem remains
 fixes problem, but unclear as to why...
Prints that show bug in asynchat that causes delays in stats_reply's to be seen in the runtime.

For example, the output below shows that a stats_reply was received in pox_client but only received in the backend and runtime 30s after.

ERROR:pyretic.core.runtime.Runtime:2013-10-28 13:56:17,687: in pull_stats: sent out stats query to switch 1
>>> 2013-10-28 13:56:17.689180 issued query, sleeping for 2.500000
INFO:Pox_client: Got flow stats request from pyretic for switch 1
INFO:Pox_client: Sent flow stats request on switch connection.
INFO:Pox_client: Received flow stats from switch 1
>>> 2013-10-28 13:56:20.193530 issued query, sleeping for 2.500000
>>> 2013-10-28 13:56:22.694500 issued query, sleeping for 2.500000
>>> 2013-10-28 13:56:25.197363 issued query, sleeping for 2.500000
>>> 2013-10-28 13:56:27.701094 issued query, sleeping for 2.500000
>>> 2013-10-28 13:56:30.204982 issued query, sleeping for 2.500000
>>> 2013-10-28 13:56:32.708270 issued query, sleeping for 2.500000
>>> 2013-10-28 13:56:35.211692 issued query, sleeping for 2.500000
>>> 2013-10-28 13:56:37.715335 issued query, sleeping for 2.500000
>>> 2013-10-28 13:56:40.218597 issued query, sleeping for 2.500000
>>> 2013-10-28 13:56:42.721757 issued query, sleeping for 2.500000
>>> 2013-10-28 13:56:45.226358 issued query, sleeping for 2.500000
INFO:Backend: Received a flow_stats_reply from pox_client
ERROR:pyretic.core.runtime.Runtime:2013-10-28 13:56:47,728: received a flow stats reply from switch 1
>>> 2013-10-28 13:56:47.729069 issued query, sleeping for 2.500000
*** 2013-10-28 13:56:47.741465 | In user callback for bucket 36589776
(packet, byte) counts: [0, 0]