The url loader works like the file loader, but can return a Data Url if the file is smaller than a limit.
The limit can be specified with a query parameter. (Defaults to no limit)
If the file is greater than the limit the file-loader is used and all query parameters are passed to it.
require("url?limit=10000!./file.png");
// => DataUrl if "file.png" is smaller that 10kb
require("url?mimetype=image/png!./file.png");
// => Specify mimetype for the file (Otherwise it's inferred from extension.)
require("url?prefix=img/!./file.png");
// => Parameters for the file-loader are valid too
// They are passed to the file-loader if used.