* Fix prehog protos package name
* sync prehog/v1alpha/teleport.proto from cloud
* AggregatingUsageReporter
* graceful stopping
* alerts WIP
* Split reporter and submitter
* batch_uuid
* Naming
* more naming
* Move backend stuff in a "service" object
* Return the correct err from gracefulstop
* Tweak alert link
* Better field comments
* payloadContext rather than a manual type assertion
* Rework reporter logic
* Close the base context at the end of run
* Use the count parameter in listUserActivityReports
* Use ttl parameter in createUserActivityReportsLock
* service tests
* submitter test
* reporter test
* Document GracefulStopper.GracefulStop
* Fix errorf/warnf that don't need formatting
* Add debug line on a successful report
* fix license
* sync prehog proto from cloud
* Only send non-nil events through test channel
This fixes a hang/data race, as we effectively "send" a nil event
whenever the ticker hits
* Docs and variable names
* Add some debug info to the lock and the alert
* Sync prehog protos from cloud
This includes a move to prehog.v1 for the new rpc and messages
* mechanical: rename imports of prehog/v1alpha
This renames imports of ".../prehog/v1alpha" from prehogv1a to prehogv1,
and imports of ".../prehog/v1alpha/prehogv1alphaconnect" from prehogv1c
to prehogv1ac, to avoid confusion with imports of the newly added
".../prehog/v1" and ".../prehog/v1/prehogv1connect".
* Merge remote-tracking branch 'origin/master' into espadolini/usagereporter-onprem
