Fix README link to javascript docs

Update to organization change (azavea -> OpenTreeMap)
Update to correct file (filterStringToWhere.html -> filterObjectToWhere.html)
Use a different static provider (htmlpreview.github.io -> rawgithub.com)
Fix lint
Add support for udf collection value filters

UDCV filters come in the form:
{"udf:<modelName>:<udfFieldDefId>:<udcvMemberName>": <value-or-predicate>}
Example:
{"udf:tree:18.climbCount": {"IS": 10}}
Convert makeSql to unix line endings