find a good home for reflection map-specific config/metadata

[terraswat]

Find a good home for the reflection config/metadata.

config/metadata used by:

The client uses this information to determine if the map group has the data required for reflection.

The data server uses this information to map:

• layout data types to stats methods
• layout data types to reflection data files
• source maps to target maps
• source maps to the sort of data a node represents

access method:

The client uses the route: /reflect/metaData/mapId/

The data server reads the reflection.json file from somewhere on the data server

[terraswat]

Pros for locating the reflection config/metadata with the server rather than the data:

• developers can see the reflection config/metadata for all map groups in one file

Pros for locating the reflection config/metadata with the data rather than the server:

• a strategy, location and API already exist to find data files outside of data/view *regardless of the subject matter, before introducing a new strategy, location or api, there should be an overwhelming reason not to use what exists
• all of the data and metadata for a map is contained under the dataRoot, making copying or removal of the map more obvious
• somehow it seems better for the client to retrieve map config/metadata from the data domain rather than the data server domain