the attributes of the config *.json in the code doesn't match to wiki doc.

[nanli-emory]

problems found:

• dataSource.json
  sourceType
  docs: json, csv, rest/json, rest/csv, odbc
  code: csvFile, jsonFile, csvREST, jsonREST
  dataAttributes is optional?

• dataDescription.json
  need more specific explanation. docs and code have totally different json dscription. 'visual', 'key', 'filtering'

enhance the docs later