Moved checkpoint model to new module, code refactoring, style tweaks
Another refactor
Added tests to ewsghana custom module
Tweak in global stats and commtrack settings
Merge branch 'master' into logistics-models

Conflicts:
	custom/ilsgateway/tanzania/warehouse_updater.py
	custom/ilsgateway/tasks.py
Style tweaks
Merge pull request #4842 from lwyszomi/logistics-models

EWS and ILSGateway custom modules refactoring