Add a configuration option for Journal Managers to limit the upload filesize and filetypes for non-authorized users, eg. Authors and Reviewers. The configuration option should appear in Journal Setup Step 3, possibly in 3.1, and should encompass the following: 

-- allow submission files to be limited by extension (eg. doc, wpd, odt, png, etc.)
-- allow submission files to be limited by size (eg. max size: 10MB)
-- show the relevant PHP/server max upload filesize directive values, so that the JM knows they aren't setting a value that's higher than what the server allows
-- disable the checks if values are left empty

On submission, the following information should be displayed, if configured, and of course checked against: 

-- permitted file types
-- maximum file size

This should apply to submission files; supplementary files; and possibly editorial/review files (although not so important there).