Rename "schema/v1/core" to "schema/v1/core-event-schema".
Add self-referential symlinks to schema/v1/core-event-schema
The python json schema libraries expect that relative references are
relative to the file they are in. The node json schema libraries
expect that relateive references are relative to the first file loaded.
To support both kinds we reference the core event schema using
"core-event-schema/event.json". We then symlink the core-event-schema
directory to both the location of the file refering to "event.json" so
that it will work in python and to the location of the top level file
so that it will work in node.
