#3667: Set a file's type based only on its extension.
#3667: Set file type with extension
#3667: Begin the form
#3667: Title, description for field. Prevent nonexistent file types from being added to field.
#3667: Fix bugs in the form.
#3667: Update all the upload form behaviors to support extension-only handling.
#3667: Add the mimetypes that do exist.
#3667: Update to revert file types.
#3667: Add doc text to update hook
Merge pull request #4149 from openscholar/3667-weird_file_types

Handle unknown file types