Given a req, extract the multipart form params into a (Map[String, Seq[String]], Map[String, Seq[FileItem]], request).
Given a req, extract the multipart form params into a (Map[String, Seq[String]], Map[String, Seq[FileItem]], request). The Map is assigned a default value of Nil, so param("p") would return Nil if there is no such parameter, or (as normal for servlets) a single empty string if the parameter was supplied without a value.
the number of bytes to load a file into memory before writing to disk
the directory to write temp files to
Base trait for disk-based multi part form data extraction