make use of case query methods
check keys is None exlicitly
move case status constants to casexml app
move hqcase query to hqcase app
Merge branch 'master' into casequery

Conflicts:
	corehq/apps/cloudcare/api.py
	corehq/apps/hqcase/utils.py
bump sqlagg version
if keys supplied only return matching keys
Merge pull request #710 from dimagi/casequery

make use of case query methods
Merge pull request #787 from dimagi/repkey

check keys is None exlicitly
Create commcaresettings-README.md
Update commcaresettings-README.md introduction
Merge pull request #792 from dimagi/commcaresettings-readme

Commcaresettings readme
Merge pull request #788 from dimagi/sqlagg

bump sqlagg version
Merge pull request #790 from dimagi/ret_keys

if keys supplied to indicator set only return matching keys
Merge branch 'master' into caseupdates

Conflicts:
	corehq/apps/callcenter/indicator_sets.py
matchers no longer required