init metadata module
extending DB broker
metadata table creation
Update server.py

Added query to insert/update account metadata -- similar queries for other types to follow
Update server.py

Replacing unique indices with constraints on item names.
expanding metadata server

The metadata server should follow the other server types fairly closely
with an exception: we're only supporting SQL here.
Wrote swift/metadata/utils.py

GET request *should* work
wrote in POST handler

removed everything besides POST and GET, since that's what we're
focusing on for this project.
Merge branch 'metadata_broker'