MAXSTRING Error when stream property data is too big

> We ran into a problem with [isc.rest](http://isc.rest/) using streams to save attachments. It seems like its using the JSONExportToString by default if a property is a stream, and then giving a MAXSTRING error if the stream is too big.
>
> This is the error we are getting when the steam data is too large:
>
> { "errors": [ { "error": "Error #5002: ObjectScript error: %JSONImportInternal+100^.......", "code": 5002, "domain": "%ObjectErrors", "id": "ObjectScriptError", "params": [ "%JSONImportInternal+100^......." ] } ], "summary": "Error #5002: ObjectScript error: %JSONImportInternal+100^......." }

From https://github.com/intersystems/isc-rest/issues/36