Scan operation only discovers a max of 16 files when the files pattern only matches a single directory

When the files pattern on a scan entry only matches a single directory, the operation only discovers a max of 16 files. (16 is the default high water mark for a readable object stream in Node.js). This is due to a bug in the glob-stream library, which the scan operation uses to match files. See https://github.com/gulpjs/glob-stream/issues/112. This probably can be solved either by using glob-stream's readable class directly, or upgrading glob-stream.