Fix stock status result

Was previously using hard coded min/max values for months of stock so
the reports were broken.
Update casexml
Merge branch 'master' into stock-status-fix-again

Conflicts:
	submodules/casexml-src
Move StockState from casexml / add data migration
Merge branch 'master' into stock-status-fix-again

Conflicts:
	submodules/casexml-src
Merge branch 'master' into stock-status-fix-again

Conflicts:
	corehq/apps/reports/commtrack/data_sources.py
Fix import issues
Memoize `get_domain` property
Merge pull request #2709 from dimagi/stock-status-fix-again

Fix stock status result