Add support for v2 endpoints in config.
Add send_to_endpoint handler on outbound resource.
Update send_to_endpoint to allow null content and have nicer error messages (and not use inlineCallbacks).
Add tests for send_to_endpoint.
Add test for sandbox version 2 style endpoints.
Remove ancient TODO that was resolved a long time ago.
Remove non-unicode endpoints from the endpoint list.
Merge branch 'feature/issue-889-v2-jsbox-endpoints' into develop