Add cluster file importer
Add cluster file importer

From https://github.com/eHealthAfrica/eha-nutsurv-django/issues/516#issuecomment-118028368

Connects #516.

johanneswilm/eha-nutsurv-django,eHealthAfrica/nutsurv,johanneswilm/eha-nutsurv-django,eHealthAfrica/nutsurv,johanneswilm/eha-nutsurv-django,eHealthAfrica/nutsurv