Send notifications through the Elgg 1.9 notifications system.
Fixes notification summary translation.
Merge pull request #11 from juho-jaakkola/get_subscriptions

Send notifications through the Elgg 1.9 notifications system.
Merge pull request #12 from juho-jaakkola/translate_notification_summary

Fixes notification summary translation.
Fixes fatal error caused by not finding any subscribers.

The subscriptions hook was assuming that there will always be subscribers. Now it checks whether there are any before it attempts to proceed.
Merge pull request #13 from juho-jaakkola/handle_no_subscribers

Fixes fatal error caused by not finding any subscribers