use new ReadOnlyObject object to memoize properties (accessing a couchdbkit seems to rewrap every time)

this cuts calcalation time in half for bihar
bump dimag-utils version
Merge pull request #16 from dimagi/read_only

use new ReadOnlyObject object to memoize properties (accessing a couchdb...
Merge branch 'master' into sync_docs

Conflicts:
	setup.py